diff --git a/fastNLP/core/callbacks/torch_callbacks/torch_lr_sched_callback.py b/fastNLP/core/callbacks/torch_callbacks/torch_lr_sched_callback.py
index 07c3c612..97e1c544 100644
--- a/fastNLP/core/callbacks/torch_callbacks/torch_lr_sched_callback.py
+++ b/fastNLP/core/callbacks/torch_callbacks/torch_lr_sched_callback.py
@@ -41,10 +41,9 @@ class TorchWarmupCallback(Callback):
         return max((progress - 1.) / (self.warmup - 1.), 0.)
 
     def on_train_begin(self, trainer):
-        self.t_steps = trainer.n_batches
         if self.warmup >1:
-            self.warmup = self.warmup / self.t_steps
-        self.t_steps = max(2, self.t_steps)  # 不能小于2
+            self.warmup = self.warmup / trainer.n_batches
+        self.t_steps = max(2, trainer.n_batches)  # 不能小于2
         # 防止 t_steps 不能整除 accumulation_steps
         self.t_steps = math.ceil(self.t_steps/trainer.accumulation_steps) * trainer.accumulation_steps
         # 获取param_group的初始learning rate
diff --git a/fastNLP/core/collators/collator.py b/fastNLP/core/collators/collator.py
index 0ff9fb2a..5a3b1967 100644
--- a/fastNLP/core/collators/collator.py
+++ b/fastNLP/core/collators/collator.py
@@ -107,7 +107,7 @@ class Collator:
     如果需要某些 field 不要包含在 pad 之后的结果中，可以使用 :meth:`~fastNLP.Collator.set_ignore` 进行设置。
 
     Collator 在第一次进行 pad 的时候自动根据设置以及数据情况，为每个 field 获取一个 padder ，在之后的每次调用中，都将使用对应
-    的 Padder 给对应的 field 。
+    的 Padder 给对应的 field 。由于 Collator 只能在某个 field 内进行 pad ，如果 pad 操作需要同时操作多个 field ，请不要使用 Collator 。
 
     :param backend: 对于可以 pad 的 field，使用哪种 tensor，支持 ``['torch','jittor','paddle','oneflow','numpy','raw', 'auto', None]``。
         若为 ``'auto'`` ，则在进行 pad 的时候会根据调用的环境决定其 ``backend`` 。该参数对不能进行 pad 的数据没有影响，无法 pad 的数据返回一定
diff --git a/fastNLP/core/controllers/utils/utils.py b/fastNLP/core/controllers/utils/utils.py
index 0a351354..ca1e0b86 100644
--- a/fastNLP/core/controllers/utils/utils.py
+++ b/fastNLP/core/controllers/utils/utils.py
@@ -132,6 +132,17 @@ class _TruncatedDataLoader:
     def __getattr__(self, item):
         return getattr(self.dataloader, item)
 
+    def __setattr__(self, key, value):
+        # 添加该函数使得在进行实验性训练或者评测时，用户对于 trainer.dataloader 的感觉和正常训练完全一样；
+        # 注意这里不能直接 ``setattr(self.dataloader, key, value)``，会导致死循环；
+        if "dataloader" in self.__dict__:
+            if hasattr(self.dataloader, key):
+                setattr(self.dataloader, key, value)
+            else:
+                self.__dict__[key] = value
+        else:
+            self.__dict__[key] = value
+
 
 def check_evaluate_every(evaluate_every):
     r"""
diff --git a/fastNLP/core/metrics/element.py b/fastNLP/core/metrics/element.py
index 5a52e4fa..359df3b8 100644
--- a/fastNLP/core/metrics/element.py
+++ b/fastNLP/core/metrics/element.py
@@ -88,7 +88,7 @@ class Element:
         """
         重置 value
         """
-        if self.backend.is_specified():
+        if self.backend.is_specified() and self._value is not None:
             self._value = self.backend.fill_value(self._value, self.init_value)
 
     @property
diff --git a/fastNLP/io/utils.py b/fastNLP/io/utils.py
index a3af71f5..c53d6158 100644
--- a/fastNLP/io/utils.py
+++ b/fastNLP/io/utils.py
@@ -52,8 +52,8 @@ def check_loader_paths(paths: Union[str, Dict[str, str]]) -> Dict[str, str]:
                     path_pair = ('test', filename)
                 if path_pair:
                     if path_pair[0] in files:
-                        raise FileExistsError(f"Two files contain `{path_pair[0]}` were found, please specify the "
-                                              f"filepath for `{path_pair[0]}`.")
+                        raise FileExistsError(f"Two files contain `{path_pair[0]}` were found in {paths}, please specify "
+                                              f"the filepath for `{path_pair[0]}`.")
                     files[path_pair[0]] = os.path.join(paths, path_pair[1])
             # if 'train' not in files:
             #     raise KeyError(f"There is no train file in {paths}.")
diff --git a/setup.py b/setup.py
index 21e4c0e4..a3447bf2 100644
--- a/setup.py
+++ b/setup.py
@@ -16,7 +16,7 @@ print(pkgs)
 
 setup(
     name='FastNLP',
-    version='1.0.0alpha',
+    version='1.0.0beta',
     url='https://gitee.com/fastnlp/fastNLP',
     description='fastNLP: Deep Learning Toolkit for NLP, developed by Fudan FastNLP Team',
     long_description=readme,