diff --git a/x2paddle/convert.py b/x2paddle/convert.py
index 294e1f0d65c1335bc3f47f48c9a6e57a584804a3..11420b67c27edd70e33837f55d81f54289c298b1 100644
--- a/x2paddle/convert.py
+++ b/x2paddle/convert.py
@@ -49,7 +49,7 @@ def arg_parser():
         "--caffe_proto",
         "-c",
         type=_text_type,
-        default='./x2paddle/decoder/caffe_pb2.py',
+        default=None,
         help="the .py file compiled by caffe proto file of caffe model")
     parser.add_argument("--version",
                         "-v",
@@ -91,10 +91,6 @@ def tf2paddle(model_path, save_dir):
 
 
 def caffe2paddle(proto, weight, save_dir, caffe_proto):
-    import os
-    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
     from x2paddle.decoder.caffe_decoder import CaffeDecoder
     from x2paddle.op_mapper.caffe_op_mapper import CaffeOpMapper
 
diff --git a/x2paddle/decoder/caffe_decoder.py b/x2paddle/decoder/caffe_decoder.py
index c3d3edabaf3ac8e09b879fbc582e93ddf4e9f85b..d6a925170d259332e7d1cc7f89bf935696ceca16 100644
--- a/x2paddle/decoder/caffe_decoder.py
+++ b/x2paddle/decoder/caffe_decoder.py
@@ -146,6 +146,11 @@ class CaffeDecoder(object):
     def __init__(self, proto_path, model_path, caffe_proto):
         self.proto_path = proto_path
         self.model_path = model_path
+        if caffe_proto is None:
+            caffe_proto = './x2paddle/decoder/caffe_pb2.py'
+        if caffe_proto is not None and not os.path.isfile(caffe_proto):
+            raise Exception(
+                "The .py file compiled by caffe.proto is not exist.")
 
         self.resolver = CaffeResolver(caffe_proto=caffe_proto)
         self.net = self.resolver.NetParameter()