diff --git a/pyspider/database/mongodb/taskdb.py b/pyspider/database/mongodb/taskdb.py
index 5b65ba6ea..8d7721c62 100644
--- a/pyspider/database/mongodb/taskdb.py
+++ b/pyspider/database/mongodb/taskdb.py
@@ -45,7 +45,7 @@ def _parse(self, data):
                 if data[each]:
                     if isinstance(data[each], bytearray):
                         data[each] = str(data[each])
-                    data[each] = json.loads(data[each], encoding='utf8')
+                    data[each] = json.loads(data[each])
                 else:
                     data[each] = {}
         return data