diff --git a/x2paddle/convert.py b/x2paddle/convert.py
index 44a78ee876d67c729b6f39f6cb43b377c73501a4..5749de6a51ea3347577bc8fbff4f226dd9ec1107 100644
--- a/x2paddle/convert.py
+++ b/x2paddle/convert.py
@@ -45,11 +45,12 @@ def arg_parser():
                         type=_text_type,
                         default=None,
                         help="define which deeplearning framework")
-    parser.add_argument("--caffe_proto",
-                        "-c",
-                        type=_text_type,
-                        default='./x2paddle/decoder/caffe_pb2.py',
-                        help="caffe proto file of caffe model")
+    parser.add_argument(
+        "--caffe_proto",
+        "-c",
+        type=_text_type,
+        default=None,
+        help="the .py file compiled by caffe proto file of caffe model")
     parser.add_argument("--version",
                         "-v",
                         action="store_true",
@@ -92,9 +93,8 @@ def tf2paddle(model_path, save_dir):
 def caffe2paddle(proto, weight, save_dir, caffe_proto):
     if caffe_proto is not None:
         import os
-        print(caffe_proto)
-        if caffe_proto != 'None' and not os.path.isfile(caffe_proto):
-            print("The file that resolve caffe is not exist.")
+        if caffe_proto is not None and not os.path.isfile(caffe_proto):
+            print("The .py file compiled by caffe.proto is not exist.")
             return
     else:
         try:
diff --git a/x2paddle/decoder/caffe_decoder.py b/x2paddle/decoder/caffe_decoder.py
index c284b7252df5d2e0e476c93709ccc2800ae74083..5795dff91c4c410bd320c044c2ff146f3742e91b 100644
--- a/x2paddle/decoder/caffe_decoder.py
+++ b/x2paddle/decoder/caffe_decoder.py
@@ -24,7 +24,7 @@ from x2paddle.op_mapper import caffe_shape
 class CaffeResolver(object):
     def __init__(self, caffe_proto):
         self.proto_path = caffe_proto
-        if self.proto_path == 'None':
+        if self.proto_path is None:
             self.use_default = True
         else:
             self.use_default = False
@@ -143,11 +143,12 @@ class CaffeGraph(Graph):
                                      ]))).to_proto().layer[0])
                     except:
                         print(
-                            "The .py fiel compiled by .proto file does not work for the old style prototxt. "
+                            "The .py file compiled by .proto file does not work for the old style prototxt. "
                         )
                         print("There are 2 solutions for you as below:")
                         print(
-                            "1. install caffe and set \'--caffe_proto=None\'.")
+                            "1. install caffe and don\'t set \'--caffe_proto\'."
+                        )
                         print(
                             "2. modify your .prototxt from the old style to the new style."
                         )
@@ -166,11 +167,12 @@ class CaffeGraph(Graph):
                                      ]))).to_proto().layer[0])
                     except:
                         print(
-                            "The .py fiel compiled by .proto file does not work for the old style prototxt. "
+                            "The .py file compiled by .proto file does not work for the old style prototxt. "
                         )
                         print("There are 2 solutions for you as below:")
                         print(
-                            "1. install caffe and set \'--caffe_proto=None\'.")
+                            "1. install caffe and don\'t set \'--caffe_proto\'."
+                        )
                         print(
                             "2. modify your .prototxt from the old style to the new style."
                         )
@@ -219,10 +221,7 @@ class CaffeGraph(Graph):
 
 
 class CaffeDecoder(object):
-    def __init__(self,
-                 proto_path,
-                 model_path,
-                 caffe_proto='./x2paddle/decoder/caffe_pb2.py'):
+    def __init__(self, proto_path, model_path, caffe_proto=None):
         self.proto_path = proto_path
         self.model_path = model_path