diff --git a/fastNLP/core/preprocess.py b/fastNLP/core/preprocess.py
index 90a32c12..77df6b51 100644
--- a/fastNLP/core/preprocess.py
+++ b/fastNLP/core/preprocess.py
@@ -97,7 +97,8 @@ class BasePreprocess(object):
                 save_pickle(data_train, pickle_path, "data_train.pkl")
             else:
                 data_train = load_pickle(pickle_path, "data_train.pkl")
-                data_dev = load_pickle(pickle_path, "data_dev.pkl")
+                if pickle_exist(pickle_path, "data_dev.pkl"):
+                    data_dev = load_pickle(pickle_path, "data_dev.pkl")
         else:
             # cross_val is True
             if not pickle_exist(pickle_path, "data_train_0.pkl"):
@@ -307,4 +308,4 @@ def infer_preprocess(pickle_path, data):
     data_index = []
     for example in data:
         data_index.append([word2index.get(w, DEFAULT_UNKNOWN_LABEL) for w in example])
-    return data_index
\ No newline at end of file
+    return data_index