diff --git a/fastNLP/core/metrics.py b/fastNLP/core/metrics.py
index 0dc601a3..b06e5459 100644
--- a/fastNLP/core/metrics.py
+++ b/fastNLP/core/metrics.py
@@ -24,7 +24,7 @@ from .utils import seq_len_to_mask
 from .vocabulary import Vocabulary
 from abc import abstractmethod
 import warnings
-
+from typing import Union
 
 class MetricBase(object):
     """
@@ -337,15 +337,18 @@ class AccuracyMetric(MetricBase):
             raise TypeError(f"`seq_lens` in {_get_func_signature(self.evaluate)} must be torch.Tensor,"
                             f"got {type(seq_len)}.")
         
-        if seq_len is not None:
-            masks = seq_len_to_mask(seq_len=seq_len)
+        if seq_len is not None and target.dim()>1:
+            max_len = target.size(1)
+            masks = seq_len_to_mask(seq_len=seq_len, max_len=max_len)
         else:
             masks = None
         
-        if pred.size() == target.size():
+        if pred.dim() == target.dim():
             pass
-        elif len(pred.size()) == len(target.size()) + 1:
+        elif pred.dim() == target.dim() + 1:
             pred = pred.argmax(dim=-1)
+            if seq_len is None:
+                warnings.warn("You are not passing `seq_len` to exclude pad when calculate accuracy.")
         else:
             raise RuntimeError(f"In {_get_func_signature(self.evaluate)}, when pred have "
                                f"size:{pred.size()}, target should have size: {pred.size()} or "
@@ -493,20 +496,63 @@ def _bio_tag_to_spans(tags, ignore_labels=None):
     return [(span[0], (span[1][0], span[1][1] + 1)) for span in spans if span[0] not in ignore_labels]
 
 
-def _check_tag_vocab_and_encoding_type(vocab:Vocabulary, encoding_type:str):
+def _get_encoding_type_from_tag_vocab(tag_vocab:Union[Vocabulary, dict])->str:
+    """
+    给定Vocabulary自动判断是哪种类型的encoding, 支持判断bmes, bioes, bmeso, bio
+
+    :param tag_vocab: 支持传入tag Vocabulary; 或者传入形如{0:"O", 1:"B-tag1"}，即index在前，tag在后的dict。
+    :return:
+    """
+    tag_set = set()
+    unk_token = '<unk>'
+    pad_token = '<pad>'
+    if isinstance(tag_vocab, Vocabulary):
+        unk_token = tag_vocab.unknown
+        pad_token = tag_vocab.padding
+        tag_vocab = tag_vocab.idx2word
+    for idx, tag in tag_vocab.items():
+        if tag in (unk_token, pad_token):
+            continue
+        tag = tag[:1].lower()
+        tag_set.add(tag)
+
+    bmes_tag_set = set('bmes')
+    if tag_set == bmes_tag_set:
+        return 'bmes'
+    bio_tag_set = set('bio')
+    if tag_set == bio_tag_set:
+        return 'bio'
+    bmeso_tag_set = set('bmeso')
+    if tag_set == bmeso_tag_set:
+        return 'bmeso'
+    bioes_tag_set = set('bioes')
+    if tag_set == bioes_tag_set:
+        return 'bioes'
+    raise RuntimeError("encoding_type cannot be inferred automatically. Only support "
+                       "'bio', 'bmes', 'bmeso', 'bioes' type.")
+
+
+def _check_tag_vocab_and_encoding_type(tag_vocab:Union[Vocabulary, dict], encoding_type:str):
     """
     检查vocab中的tag是否与encoding_type是匹配的
 
-    :param vocab: target的Vocabulary
+    :param tag_vocab: 支持传入tag Vocabulary; 或者传入形如{0:"O", 1:"B-tag1"}，即index在前，tag在后的dict。
     :param encoding_type: bio, bmes, bioes, bmeso
     :return:
     """
     tag_set = set()
-    for tag, idx in vocab:
-        if idx in (vocab.unknown_idx, vocab.padding_idx):
+    unk_token = '<unk>'
+    pad_token = '<pad>'
+    if isinstance(tag_vocab, Vocabulary):
+        unk_token = tag_vocab.unknown
+        pad_token = tag_vocab.padding
+        tag_vocab = tag_vocab.idx2word
+    for idx, tag in tag_vocab.items():
+        if tag in (unk_token, pad_token):
             continue
         tag = tag[:1].lower()
         tag_set.add(tag)
+
     tags = encoding_type
     for tag in tag_set:
         assert tag in tags, f"{tag} is not a valid tag in encoding type:{encoding_type}. Please check your " \
@@ -549,7 +595,7 @@ class SpanFPreRecMetric(MetricBase):
     :param str pred: 用该key在evaluate()时从传入dict中取出prediction数据。 为None，则使用 `pred` 取数据
     :param str target: 用该key在evaluate()时从传入dict中取出target数据。 为None，则使用 `target` 取数据
     :param str seq_len: 用该key在evaluate()时从传入dict中取出sequence length数据。为None，则使用 `seq_len` 取数据。
-    :param str encoding_type: 目前支持bio, bmes, bmeso, bioes
+    :param str encoding_type: 目前支持bio, bmes, bmeso, bioes。默认为None，通过tag_vocab自动判断.
     :param list ignore_labels: str 组成的list. 这个list中的class不会被用于计算。例如在POS tagging时传入['NN']，则不会计算'NN'这
         个label
     :param bool only_gross: 是否只计算总的f1, precision, recall的值；如果为False，不仅返回总的f1, pre, rec, 还会返回每个
@@ -560,18 +606,21 @@ class SpanFPreRecMetric(MetricBase):
         常用为beta=0.5, 1, 2. 若为0.5则精确率的权重高于召回率；若为1，则两者平等；若为2，则召回率权重高于精确率。
     """
     
-    def __init__(self, tag_vocab, pred=None, target=None, seq_len=None, encoding_type='bio', ignore_labels=None,
+    def __init__(self, tag_vocab, pred=None, target=None, seq_len=None, encoding_type=None, ignore_labels=None,
                  only_gross=True, f_type='micro', beta=1):
-        
-        encoding_type = encoding_type.lower()
-        
+
         if not isinstance(tag_vocab, Vocabulary):
             raise TypeError("tag_vocab can only be fastNLP.Vocabulary, not {}.".format(type(tag_vocab)))
         if f_type not in ('micro', 'macro'):
             raise ValueError("f_type only supports `micro` or `macro`', got {}.".format(f_type))
-        
-        self.encoding_type = encoding_type
-        _check_tag_vocab_and_encoding_type(tag_vocab, encoding_type)
+
+        if encoding_type:
+            encoding_type = encoding_type.lower()
+            _check_tag_vocab_and_encoding_type(tag_vocab, encoding_type)
+            self.encoding_type = encoding_type
+        else:
+            self.encoding_type =  _get_encoding_type_from_tag_vocab(tag_vocab)
+
         if self.encoding_type == 'bmes':
             self.tag_to_span_func = _bmes_tag_to_spans
         elif self.encoding_type == 'bio':
@@ -581,7 +630,7 @@ class SpanFPreRecMetric(MetricBase):
         elif self.encoding_type == 'bioes':
             self.tag_to_span_func = _bioes_tag_to_spans
         else:
-            raise ValueError("Only support 'bio', 'bmes', 'bmeso' type.")
+            raise ValueError("Only support 'bio', 'bmes', 'bmeso', 'bioes' type.")
         
         self.ignore_labels = ignore_labels
         self.f_type = f_type
diff --git a/fastNLP/core/vocabulary.py b/fastNLP/core/vocabulary.py
index cd4f2c0f..b0f9650a 100644
--- a/fastNLP/core/vocabulary.py
+++ b/fastNLP/core/vocabulary.py
@@ -39,7 +39,7 @@ def _check_build_vocab(func):
     
     @wraps(func)  # to solve missing docstring
     def _wrapper(self, *args, **kwargs):
-        if self.word2idx is None or self.rebuild is True:
+        if self._word2idx is None or self.rebuild is True:
             self.build_vocab()
         return func(self, *args, **kwargs)
     
@@ -95,12 +95,30 @@ class Vocabulary(object):
         self.word_count = Counter()
         self.unknown = unknown
         self.padding = padding
-        self.word2idx = None
-        self.idx2word = None
+        self._word2idx = None
+        self._idx2word = None
         self.rebuild = True
         #  用于承载不需要单独创建entry的词语，具体见from_dataset()方法
         self._no_create_word = Counter()
-    
+
+    @property
+    @_check_build_vocab
+    def word2idx(self):
+        return self._word2idx
+
+    @word2idx.setter
+    def word2idx(self, value):
+        self._word2idx = value
+
+    @property
+    @_check_build_vocab
+    def idx2word(self):
+        return self._idx2word
+
+    @idx2word.setter
+    def idx2word(self, value):
+        self._word2idx = value
+
     @_check_build_status
     def update(self, word_lst, no_create_entry=False):
         """依次增加序列中词在词典中的出现频率
@@ -187,21 +205,21 @@ class Vocabulary(object):
         但已经记录在词典中的词, 不会改变对应的 `int`
 
         """
-        if self.word2idx is None:
-            self.word2idx = {}
+        if self._word2idx is None:
+            self._word2idx = {}
             if self.padding is not None:
-                self.word2idx[self.padding] = len(self.word2idx)
+                self._word2idx[self.padding] = len(self._word2idx)
             if self.unknown is not None:
-                self.word2idx[self.unknown] = len(self.word2idx)
+                self._word2idx[self.unknown] = len(self._word2idx)
         
         max_size = min(self.max_size, len(self.word_count)) if self.max_size else None
         words = self.word_count.most_common(max_size)
         if self.min_freq is not None:
             words = filter(lambda kv: kv[1] >= self.min_freq, words)
-        if self.word2idx is not None:
-            words = filter(lambda kv: kv[0] not in self.word2idx, words)
-        start_idx = len(self.word2idx)
-        self.word2idx.update({w: i + start_idx for i, (w, _) in enumerate(words)})
+        if self._word2idx is not None:
+            words = filter(lambda kv: kv[0] not in self._word2idx, words)
+        start_idx = len(self._word2idx)
+        self._word2idx.update({w: i + start_idx for i, (w, _) in enumerate(words)})
         self.build_reverse_vocab()
         self.rebuild = False
         return self
@@ -211,12 +229,12 @@ class Vocabulary(object):
         基于 `word to index` dict, 构建 `index to word` dict.
 
         """
-        self.idx2word = {i: w for w, i in self.word2idx.items()}
+        self._idx2word = {i: w for w, i in self._word2idx.items()}
         return self
     
     @_check_build_vocab
     def __len__(self):
-        return len(self.word2idx)
+        return len(self._word2idx)
     
     @_check_build_vocab
     def __contains__(self, item):
@@ -226,7 +244,7 @@ class Vocabulary(object):
         :param item: the word
         :return: True or False
         """
-        return item in self.word2idx
+        return item in self._word2idx
     
     def has_word(self, w):
         """
@@ -248,10 +266,10 @@ class Vocabulary(object):
 
             vocab[w]
         """
-        if w in self.word2idx:
-            return self.word2idx[w]
+        if w in self._word2idx:
+            return self._word2idx[w]
         if self.unknown is not None:
-            return self.word2idx[self.unknown]
+            return self._word2idx[self.unknown]
         else:
             raise ValueError("word `{}` not in vocabulary".format(w))
     
@@ -405,7 +423,7 @@ class Vocabulary(object):
         """
         if self.unknown is None:
             return None
-        return self.word2idx[self.unknown]
+        return self._word2idx[self.unknown]
     
     @property
     @_check_build_vocab
@@ -415,7 +433,7 @@ class Vocabulary(object):
         """
         if self.padding is None:
             return None
-        return self.word2idx[self.padding]
+        return self._word2idx[self.padding]
     
     @_check_build_vocab
     def to_word(self, idx):
@@ -425,7 +443,7 @@ class Vocabulary(object):
         :param int idx: the index
         :return str word: the word
         """
-        return self.idx2word[idx]
+        return self._idx2word[idx]
     
     def clear(self):
         """
@@ -434,8 +452,8 @@ class Vocabulary(object):
         :return:
         """
         self.word_count.clear()
-        self.word2idx = None
-        self.idx2word = None
+        self._word2idx = None
+        self._idx2word = None
         self.rebuild = True
         self._no_create_word.clear()
         return self
@@ -446,8 +464,8 @@ class Vocabulary(object):
         """
         len(self)  # make sure vocab has been built
         state = self.__dict__.copy()
-        # no need to pickle idx2word as it can be constructed from word2idx
-        del state['idx2word']
+        # no need to pickle _idx2word as it can be constructed from _word2idx
+        del state['_idx2word']
         return state
     
     def __setstate__(self, state):
@@ -462,5 +480,5 @@ class Vocabulary(object):
     
     @_check_build_vocab
     def __iter__(self):
-        for word, index in self.word2idx.items():
+        for word, index in self._word2idx.items():
             yield word, index
diff --git a/fastNLP/io/data_bundle.py b/fastNLP/io/data_bundle.py
index f30add34..3e7f39d3 100644
--- a/fastNLP/io/data_bundle.py
+++ b/fastNLP/io/data_bundle.py
@@ -8,7 +8,7 @@ __all__ = [
 
 from ..core.dataset import DataSet
 from ..core.vocabulary import Vocabulary
-
+from typing import Union
 
 class DataBundle:
     """
@@ -191,7 +191,7 @@ class DataBundle:
                 raise KeyError(f"{field_name} not found DataSet:{name}.")
         return self
 
-    def rename_field(self, field_name, new_field_name, ignore_miss_dataset=True):
+    def rename_field(self, field_name, new_field_name, ignore_miss_dataset=True, rename_vocab=True):
         """
         将DataBundle中所有DataSet中名为field_name的field重命名为new_field_name.
 
@@ -199,6 +199,7 @@ class DataBundle:
         :param str new_field_name:
         :param bool ignore_miss_dataset: 当某个field名称在某个dataset不存在时，如果为True，则直接忽略该DataSet;
             如果为False，则报错
+        :param bool rename_vocab: 如果该field同时也存在于vocabs中，会将该field的名称对应修改
         :return: self
         """
         for name, dataset in self.datasets.items():
@@ -206,15 +207,20 @@ class DataBundle:
                 dataset.rename_field(field_name=field_name, new_field_name=new_field_name)
             elif not ignore_miss_dataset:
                 raise KeyError(f"{field_name} not found DataSet:{name}.")
+        if rename_vocab:
+            if field_name in self.vocabs:
+                self.vocabs[new_field_name] = self.vocabs.pop(field_name)
+
         return self
 
-    def delete_field(self, field_name, ignore_miss_dataset=True):
+    def delete_field(self, field_name, ignore_miss_dataset=True, delete_vocab=True):
         """
         将DataBundle中所有DataSet中名为field_name的field删除掉.
 
         :param str field_name:
         :param bool ignore_miss_dataset: 当某个field名称在某个dataset不存在时，如果为True，则直接忽略该DataSet;
             如果为False，则报错
+        :param bool delete_vocab: 如果该field也在vocabs中存在，将该值也一并删除
         :return: self
         """
         for name, dataset in self.datasets.items():
@@ -222,8 +228,39 @@ class DataBundle:
                 dataset.delete_field(field_name=field_name)
             elif not ignore_miss_dataset:
                 raise KeyError(f"{field_name} not found DataSet:{name}.")
+        if delete_vocab:
+            if field_name in self.vocabs:
+                self.vocabs.pop(field_name)
         return self
 
+    def iter_datasets(self)->Union[str, DataSet]:
+        """
+        迭代data_bundle中的DataSet
+
+        Example::
+
+            for name, dataset in data_bundle.iter_datasets():
+                pass
+
+        :return:
+        """
+        for name, dataset in self.datasets.items():
+            yield name, dataset
+
+    def iter_vocabs(self)->Union[str, Vocabulary]:
+        """
+        迭代data_bundle中的DataSet
+
+        Example:
+
+            for field_name, vocab in data_bundle.iter_vocabs():
+                pass
+
+        :return:
+        """
+        for field_name, vocab in self.vocabs.items():
+            yield field_name, vocab
+
     def apply_field(self, func, field_name:str, new_field_name:str, ignore_miss_dataset=True,  **kwargs):
         """
         对DataBundle中所有的dataset使用apply_field方法
diff --git a/fastNLP/io/pipe/conll.py b/fastNLP/io/pipe/conll.py
index eb7d4909..2edc9008 100644
--- a/fastNLP/io/pipe/conll.py
+++ b/fastNLP/io/pipe/conll.py
@@ -193,7 +193,7 @@ class OntoNotesNERPipe(_NERPipe):
     """
     处理OntoNotes的NER数据，处理之后DataSet中的field情况为
 
-    .. csv-table:: Following is a demo layout of DataSet returned by Conll2003Loader
+    .. csv-table::
        :header: "raw_words", "words", "target", "seq_len"
 
        "[Nadim, Ladki]", "[2, 3]", "[1, 2]", 2
diff --git a/fastNLP/models/biaffine_parser.py b/fastNLP/models/biaffine_parser.py
index bead09fc..6b0829bd 100644
--- a/fastNLP/models/biaffine_parser.py
+++ b/fastNLP/models/biaffine_parser.py
@@ -207,7 +207,7 @@ class ArcBiaffine(nn.Module):
         output = dep.matmul(self.U)
         output = output.bmm(head.transpose(-1, -2))
         if self.has_bias:
-            output += head.matmul(self.bias).unsqueeze(1)
+            output = output + head.matmul(self.bias).unsqueeze(1)
         return output
 
 
@@ -234,7 +234,7 @@ class LabelBilinear(nn.Module):
         :return output: [batch, seq_len, num_cls] 每个元素对应类别的概率图
         """
         output = self.bilinear(x1, x2)
-        output += self.lin(torch.cat([x1, x2], dim=2))
+        output = output + self.lin(torch.cat([x1, x2], dim=2))
         return output
 
 
@@ -363,7 +363,7 @@ class BiaffineParser(GraphParser):
         # print('forward {} {}'.format(batch_size, seq_len))
         
         # get sequence mask
-        mask = seq_len_to_mask(seq_len).long()
+        mask = seq_len_to_mask(seq_len, max_len=length).long()
         
         word = self.word_embedding(words1)  # [N,L] -> [N,L,C_0]
         pos = self.pos_embedding(words2)  # [N,L] -> [N,L,C_1]
@@ -435,10 +435,10 @@ class BiaffineParser(GraphParser):
         """
         
         batch_size, length, _ = pred1.shape
-        mask = seq_len_to_mask(seq_len)
+        mask = seq_len_to_mask(seq_len, max_len=length)
         flip_mask = (mask == 0)
         _arc_pred = pred1.clone()
-        _arc_pred.masked_fill_(flip_mask.unsqueeze(1), -float('inf'))
+        _arc_pred = _arc_pred.masked_fill(flip_mask.unsqueeze(1), -float('inf'))
         arc_logits = F.log_softmax(_arc_pred, dim=2)
         label_logits = F.log_softmax(pred2, dim=2)
         batch_index = torch.arange(batch_size, device=arc_logits.device, dtype=torch.long).unsqueeze(1)
@@ -446,9 +446,8 @@ class BiaffineParser(GraphParser):
         arc_loss = arc_logits[batch_index, child_index, target1]
         label_loss = label_logits[batch_index, child_index, target2]
         
-        byte_mask = flip_mask.byte()
-        arc_loss.masked_fill_(byte_mask, 0)
-        label_loss.masked_fill_(byte_mask, 0)
+        arc_loss = arc_loss.masked_fill(flip_mask, 0)
+        label_loss = label_loss.masked_fill(flip_mask, 0)
         arc_nll = -arc_loss.mean()
         label_nll = -label_loss.mean()
         return arc_nll + label_nll
diff --git a/fastNLP/modules/decoder/crf.py b/fastNLP/modules/decoder/crf.py
index f63d46e3..c13ea50c 100644
--- a/fastNLP/modules/decoder/crf.py
+++ b/fastNLP/modules/decoder/crf.py
@@ -10,33 +10,45 @@ from torch import nn
 
 from ..utils import initial_parameter
 from ...core.vocabulary import Vocabulary
+from ...core.metrics import _get_encoding_type_from_tag_vocab, _check_tag_vocab_and_encoding_type
+from typing import Union
 
-
-def allowed_transitions(id2target, encoding_type='bio', include_start_end=False):
+def allowed_transitions(tag_vocab:Union[Vocabulary, dict], encoding_type=None, include_start_end=False):
     """
     别名：:class:`fastNLP.modules.allowed_transitions`  :class:`fastNLP.modules.decoder.allowed_transitions`
 
     给定一个id到label的映射表，返回所有可以跳转的(from_tag_id, to_tag_id)列表。
 
-    :param dict, ~fastNLP.Vocabulary id2target: key是label的indices，value是str类型的tag或tag-label。value可以是只有tag的, 比如"B", "M"; 也可以是
-        "B-NN", "M-NN", tag和label之间一定要用"-"隔开。一般可以通过Vocabulary.idx2word得到id2label。
-    :param str encoding_type: 支持"bio", "bmes", "bmeso", "bioes"。
+    :param ~fastNLP.Vocabulary,dict tag_vocab: 支持类型为tag或tag-label。只有tag的,比如"B", "M"; 也可以是"B-NN", "M-NN",
+        tag和label之间一定要用"-"隔开。如果传入dict，格式需要形如{0:"O", 1:"B-tag1"}，即index在前，tag在后。
+    :param str encoding_type: 支持"bio", "bmes", "bmeso", "bioes"。默认为None，通过vocab自动推断
     :param bool include_start_end: 是否包含开始与结尾的转换。比如在bio中，b/o可以在开头，但是i不能在开头；
         为True，返回的结果中会包含(start_idx, b_idx), (start_idx, o_idx), 但是不包含(start_idx, i_idx);
         start_idx=len(id2label), end_idx=len(id2label)+1。为False, 返回的结果中不含与开始结尾相关的内容
     :return: List[Tuple(int, int)]], 内部的Tuple是可以进行跳转的(from_tag_id, to_tag_id)。
     """
-    if isinstance(id2target, Vocabulary):
-        id2target = id2target.idx2word
-    num_tags = len(id2target)
+    if encoding_type is None:
+        encoding_type = _get_encoding_type_from_tag_vocab(tag_vocab)
+    else:
+        encoding_type = encoding_type.lower()
+        _check_tag_vocab_and_encoding_type(tag_vocab, encoding_type)
+
+    pad_token = '<pad>'
+    unk_token = '<unk>'
+
+    if isinstance(tag_vocab, Vocabulary):
+        id_label_lst = list(tag_vocab.idx2word.items())
+        pad_token = tag_vocab.padding
+        unk_token = tag_vocab.unknown
+    else:
+        id_label_lst = list(tag_vocab.items())
+
+    num_tags = len(tag_vocab)
     start_idx = num_tags
     end_idx = num_tags + 1
-    encoding_type = encoding_type.lower()
     allowed_trans = []
-    id_label_lst = list(id2target.items())
     if include_start_end:
         id_label_lst += [(start_idx, 'start'), (end_idx, 'end')]
-
     def split_tag_label(from_label):
         from_label = from_label.lower()
         if from_label in ['start', 'end']:
@@ -48,11 +60,11 @@ def allowed_transitions(id2target, encoding_type='bio', include_start_end=False)
         return from_tag, from_label
 
     for from_id, from_label in id_label_lst:
-        if from_label in ['<pad>', '<unk>']:
+        if from_label in [pad_token, unk_token]:
             continue
         from_tag, from_label = split_tag_label(from_label)
         for to_id, to_label in id_label_lst:
-            if to_label in ['<pad>', '<unk>']:
+            if to_label in [pad_token, unk_token]:
                 continue
             to_tag, to_label = split_tag_label(to_label)
             if _is_transition_allowed(encoding_type, from_tag, from_label, to_tag, to_label):
diff --git a/test/core/test_metrics.py b/test/core/test_metrics.py
index 5a7c55cf..8a472a62 100644
--- a/test/core/test_metrics.py
+++ b/test/core/test_metrics.py
@@ -11,6 +11,12 @@ from fastNLP.core.metrics import SpanFPreRecMetric, ExtractiveQAMetric
 
 
 def _generate_tags(encoding_type, number_labels=4):
+    """
+
+    :param encoding_type: 例如BIOES, BMES, BIO等
+    :param number_labels: 多少个label，大于1
+    :return:
+    """
     vocab = {}
     for i in range(number_labels):
         label = str(i)
@@ -184,7 +190,7 @@ class TestAccuracyMetric(unittest.TestCase):
         self.assertDictEqual(metric.get_metric(), {'acc': 1.})
 
 
-class SpanF1PreRecMetric(unittest.TestCase):
+class SpanFPreRecMetricTest(unittest.TestCase):
     def test_case1(self):
         from fastNLP.core.metrics import _bmes_tag_to_spans
         from fastNLP.core.metrics import _bio_tag_to_spans
@@ -338,6 +344,39 @@ class SpanF1PreRecMetric(unittest.TestCase):
         for key, value in expected_metric.items():
             self.assertAlmostEqual(value, metric_value[key], places=5)
 
+    def test_auto_encoding_type_infer(self):
+        #  检查是否可以自动check encode的类型
+        vocabs = {}
+        import random
+        for encoding_type in ['bio', 'bioes', 'bmeso']:
+            vocab = Vocabulary(unknown=None, padding=None)
+            for i in range(random.randint(10, 100)):
+                label = str(random.randint(1, 10))
+                for tag in encoding_type:
+                    if tag!='o':
+                        vocab.add_word(f'{tag}-{label}')
+                    else:
+                        vocab.add_word('o')
+            vocabs[encoding_type] = vocab
+        for e in ['bio', 'bioes', 'bmeso']:
+            with self.subTest(e=e):
+                metric = SpanFPreRecMetric(tag_vocab=vocabs[e])
+                assert metric.encoding_type == e
+
+        bmes_vocab = _generate_tags('bmes')
+        vocab = Vocabulary()
+        for tag, index in bmes_vocab.items():
+            vocab.add_word(tag)
+        metric = SpanFPreRecMetric(vocab)
+        assert metric.encoding_type == 'bmes'
+
+        # 一些无法check的情况
+        vocab = Vocabulary()
+        for i in range(10):
+            vocab.add_word(str(i))
+        with self.assertRaises(Exception):
+            metric = SpanFPreRecMetric(vocab)
+
     def test_encoding_type(self):
         # 检查传入的tag_vocab与encoding_type不符合时，是否会报错
         vocabs = {}
diff --git a/test/modules/decoder/test_CRF.py b/test/modules/decoder/test_CRF.py
index 647af7d3..94b4ab7a 100644
--- a/test/modules/decoder/test_CRF.py
+++ b/test/modules/decoder/test_CRF.py
@@ -1,6 +1,6 @@
 
 import unittest
-
+from fastNLP import Vocabulary
 
 class TestCRF(unittest.TestCase):
     def test_case1(self):
@@ -14,7 +14,8 @@ class TestCRF(unittest.TestCase):
 
         id2label = {0: 'B', 1:'M', 2:'E', 3:'S'}
         expected_res = {(0, 1), (0, 2), (1, 1), (1, 2), (2, 0), (2, 3), (2, 5), (3, 0), (3, 3), (3, 5), (4, 0), (4, 3)}
-        self.assertSetEqual(expected_res, set(allowed_transitions(id2label, encoding_type='BMES', include_start_end=True)))
+        self.assertSetEqual(expected_res, set(
+            allowed_transitions(id2label, encoding_type='BMES', include_start_end=True)))
 
         id2label = {0: 'B', 1: 'I', 2:'O', 3: '<pad>', 4:"<unk>"}
         allowed_transitions(id2label, include_start_end=True)
@@ -37,7 +38,100 @@ class TestCRF(unittest.TestCase):
         expected_res = {(0, 1), (0, 2), (1, 1), (1, 2), (2, 0), (2, 3), (2, 4), (2, 7), (2, 9), (3, 0), (3, 3), (3, 4),
                         (3, 7), (3, 9), (4, 5), (4, 6), (5, 5), (5, 6), (6, 0), (6, 3), (6, 4), (6, 7), (6, 9), (7, 0),
                         (7, 3), (7, 4), (7, 7), (7, 9), (8, 0), (8, 3), (8, 4), (8, 7)}
-        self.assertSetEqual(expected_res, set(allowed_transitions(id2label, encoding_type='BMES', include_start_end=True)))
+        self.assertSetEqual(expected_res, set(
+            allowed_transitions(id2label, include_start_end=True)))
+
+    def test_case11(self):
+        # 测试自动推断encoding类型
+        from fastNLP.modules.decoder.crf import allowed_transitions
+
+        id2label = {0: 'B', 1: 'I', 2: 'O'}
+        expected_res = {(0, 0), (0, 1), (0, 2), (0, 4), (1, 0), (1, 1), (1, 2), (1, 4), (2, 0), (2, 2),
+                        (2, 4), (3, 0), (3, 2)}
+        self.assertSetEqual(expected_res, set(allowed_transitions(id2label, include_start_end=True)))
+
+        id2label = {0: 'B', 1: 'M', 2: 'E', 3: 'S'}
+        expected_res = {(0, 1), (0, 2), (1, 1), (1, 2), (2, 0), (2, 3), (2, 5), (3, 0), (3, 3), (3, 5), (4, 0), (4, 3)}
+        self.assertSetEqual(expected_res, set(
+            allowed_transitions(id2label, include_start_end=True)))
+
+        id2label = {0: 'B', 1: 'I', 2: 'O', 3: '<pad>', 4: "<unk>"}
+        allowed_transitions(id2label, include_start_end=True)
+
+        labels = ['O']
+        for label in ['X', 'Y']:
+            for tag in 'BI':
+                labels.append('{}-{}'.format(tag, label))
+        id2label = {idx: label for idx, label in enumerate(labels)}
+        expected_res = {(0, 0), (0, 1), (0, 3), (0, 6), (1, 0), (1, 1), (1, 2), (1, 3), (1, 6), (2, 0), (2, 1),
+                        (2, 2), (2, 3), (2, 6), (3, 0), (3, 1), (3, 3), (3, 4), (3, 6), (4, 0), (4, 1), (4, 3),
+                        (4, 4), (4, 6), (5, 0), (5, 1), (5, 3)}
+        self.assertSetEqual(expected_res, set(allowed_transitions(id2label, include_start_end=True)))
+
+        labels = []
+        for label in ['X', 'Y']:
+            for tag in 'BMES':
+                labels.append('{}-{}'.format(tag, label))
+        id2label = {idx: label for idx, label in enumerate(labels)}
+        expected_res = {(0, 1), (0, 2), (1, 1), (1, 2), (2, 0), (2, 3), (2, 4), (2, 7), (2, 9), (3, 0), (3, 3), (3, 4),
+                        (3, 7), (3, 9), (4, 5), (4, 6), (5, 5), (5, 6), (6, 0), (6, 3), (6, 4), (6, 7), (6, 9), (7, 0),
+                        (7, 3), (7, 4), (7, 7), (7, 9), (8, 0), (8, 3), (8, 4), (8, 7)}
+        self.assertSetEqual(expected_res, set(
+            allowed_transitions(id2label, include_start_end=True)))
+
+    def test_case12(self):
+        # 测试能否通过vocab生成转移矩阵
+        from fastNLP.modules.decoder.crf import allowed_transitions
+
+        id2label = {0: 'B', 1: 'I', 2: 'O'}
+        vocab = Vocabulary(unknown=None, padding=None)
+        for idx, tag in id2label.items():
+            vocab.add_word(tag)
+        expected_res = {(0, 0), (0, 1), (0, 2), (0, 4), (1, 0), (1, 1), (1, 2), (1, 4), (2, 0), (2, 2),
+                        (2, 4), (3, 0), (3, 2)}
+        self.assertSetEqual(expected_res, set(allowed_transitions(vocab, include_start_end=True)))
+
+        id2label = {0: 'B', 1: 'M', 2: 'E', 3: 'S'}
+        vocab = Vocabulary(unknown=None, padding=None)
+        for idx, tag in id2label.items():
+            vocab.add_word(tag)
+        expected_res = {(0, 1), (0, 2), (1, 1), (1, 2), (2, 0), (2, 3), (2, 5), (3, 0), (3, 3), (3, 5), (4, 0), (4, 3)}
+        self.assertSetEqual(expected_res, set(
+            allowed_transitions(vocab, include_start_end=True)))
+
+        id2label = {0: 'B', 1: 'I', 2: 'O', 3: '<pad>', 4: "<unk>"}
+        vocab = Vocabulary()
+        for idx, tag in id2label.items():
+            vocab.add_word(tag)
+        allowed_transitions(vocab, include_start_end=True)
+
+        labels = ['O']
+        for label in ['X', 'Y']:
+            for tag in 'BI':
+                labels.append('{}-{}'.format(tag, label))
+        id2label = {idx: label for idx, label in enumerate(labels)}
+        expected_res = {(0, 0), (0, 1), (0, 3), (0, 6), (1, 0), (1, 1), (1, 2), (1, 3), (1, 6), (2, 0), (2, 1),
+                        (2, 2), (2, 3), (2, 6), (3, 0), (3, 1), (3, 3), (3, 4), (3, 6), (4, 0), (4, 1), (4, 3),
+                        (4, 4), (4, 6), (5, 0), (5, 1), (5, 3)}
+        vocab = Vocabulary(unknown=None, padding=None)
+        for idx, tag in id2label.items():
+            vocab.add_word(tag)
+        self.assertSetEqual(expected_res, set(allowed_transitions(vocab, include_start_end=True)))
+
+        labels = []
+        for label in ['X', 'Y']:
+            for tag in 'BMES':
+                labels.append('{}-{}'.format(tag, label))
+        id2label = {idx: label for idx, label in enumerate(labels)}
+        vocab = Vocabulary(unknown=None, padding=None)
+        for idx, tag in id2label.items():
+            vocab.add_word(tag)
+        expected_res = {(0, 1), (0, 2), (1, 1), (1, 2), (2, 0), (2, 3), (2, 4), (2, 7), (2, 9), (3, 0), (3, 3), (3, 4),
+                        (3, 7), (3, 9), (4, 5), (4, 6), (5, 5), (5, 6), (6, 0), (6, 3), (6, 4), (6, 7), (6, 9), (7, 0),
+                        (7, 3), (7, 4), (7, 7), (7, 9), (8, 0), (8, 3), (8, 4), (8, 7)}
+        self.assertSetEqual(expected_res, set(
+            allowed_transitions(vocab, include_start_end=True)))
+
 
     def test_case2(self):
         # 测试CRF能否避免解码出非法跃迁, 使用allennlp做了验证。