diff --git a/python/pipeline/operator.py b/python/pipeline/operator.py
index eed109e6543b27f37fafbd9ee328db8e2692166a..c228213d8b5cbacb70c1ee1e788ca5c769d82802 100644
--- a/python/pipeline/operator.py
+++ b/python/pipeline/operator.py
@@ -126,7 +126,7 @@ class Op(object):
         channel.add_producer(self.name)
         self._outputs.append(channel)
 
-    def preprocess(self, input_dicts):
+    def preprocess(self, input_dicts, private_obj):
         # multiple previous Op
         if len(input_dicts) != 1:
             raise NotImplementedError(
@@ -136,7 +136,7 @@ class Op(object):
         (_, input_dict), = input_dicts.items()
         return input_dict
 
-    def process(self, client_predict_handler, feed_dict):
+    def process(self, client_predict_handler, feed_dict, private_obj):
         err, err_info = ChannelData.check_npdata(feed_dict)
         if err != 0:
             raise NotImplementedError(
@@ -146,7 +146,7 @@ class Op(object):
         _LOGGER.debug(self._log("get call_result"))
         return call_result
 
-    def postprocess(self, input_dict, fetch_dict):
+    def postprocess(self, input_dict, fetch_dict, private_obj):
         return fetch_dict
 
     def stop(self):
@@ -197,10 +197,13 @@ class Op(object):
     def init_op(self):
         pass
 
-    def _run_preprocess(self, parsed_data, data_id, log_func):
+    def load_private_obj(self):
+        return None
+
+    def _run_preprocess(self, parsed_data, data_id, private_obj, log_func):
         preped_data, error_channeldata = None, None
         try:
-            preped_data = self.preprocess(parsed_data)
+            preped_data = self.preprocess(parsed_data, private_obj)
         except NotImplementedError as e:
             # preprocess function not implemented
             error_info = log_func(e)
@@ -227,14 +230,14 @@ class Op(object):
         return preped_data, error_channeldata
 
     def _run_process(self, client_predict_handler, preped_data, data_id,
-                     log_func):
+                     private_obj, log_func):
         midped_data, error_channeldata = None, None
         if self.with_serving:
             ecode = ChannelDataEcode.OK.value
             if self._timeout <= 0:
                 try:
                     midped_data = self.process(client_predict_handler,
-                                               preped_data)
+                                               preped_data, private_obj)
                 except Exception as e:
                     ecode = ChannelDataEcode.UNKNOW.value
                     error_info = log_func(e)
@@ -245,9 +248,8 @@ class Op(object):
                         midped_data = func_timeout.func_timeout(
                             self._timeout,
                             self.process,
-                            args=(
-                                client_predict_handler,
-                                preped_data, ))
+                            args=(client_predict_handler, preped_data,
+                                  private_obj))
                     except func_timeout.FunctionTimedOut as e:
                         if i + 1 >= self._retry:
                             ecode = ChannelDataEcode.TIMEOUT.value
@@ -277,10 +279,12 @@ class Op(object):
             midped_data = preped_data
         return midped_data, error_channeldata
 
-    def _run_postprocess(self, input_dict, midped_data, data_id, log_func):
+    def _run_postprocess(self, input_dict, midped_data, data_id, private_obj,
+                         log_func):
         output_data, error_channeldata = None, None
         try:
-            postped_data = self.postprocess(input_dict, midped_data)
+            postped_data = self.postprocess(input_dict, midped_data,
+                                            private_obj)
         except Exception as e:
             error_info = log_func(e)
             _LOGGER.error(error_info)
@@ -337,7 +341,7 @@ class Op(object):
             _LOGGER.error(log(e))
             os._exit(-1)
 
-        # load user resources
+        # init op
         try:
             if use_multithread:
                 with self._for_init_op_lock:
@@ -350,6 +354,14 @@ class Op(object):
             _LOGGER.error(log(e))
             os._exit(-1)
 
+        # load private objects (some no-thread-safe objects)
+        private_obj = None
+        try:
+            private_obj = self.load_private_obj()
+        except Exception as e:
+            _LOGGER.error(log(e))
+            os._exit(-1)
+
         self._is_run = True
         while self._is_run:
             #self._profiler_record("{}-get#{}_0".format(op_info_prefix, tid))
@@ -367,8 +379,8 @@ class Op(object):
 
             # preprecess
             self._profiler_record("{}-prep#{}_0".format(op_info_prefix, tid))
-            preped_data, error_channeldata = self._run_preprocess(parsed_data,
-                                                                  data_id, log)
+            preped_data, error_channeldata = self._run_preprocess(
+                parsed_data, data_id, private_obj, log)
             self._profiler_record("{}-prep#{}_1".format(op_info_prefix, tid))
             if error_channeldata is not None:
                 self._push_to_output_channels(error_channeldata,
@@ -378,7 +390,7 @@ class Op(object):
             # process
             self._profiler_record("{}-midp#{}_0".format(op_info_prefix, tid))
             midped_data, error_channeldata = self._run_process(
-                client_predict_handler, preped_data, data_id, log)
+                client_predict_handler, preped_data, data_id, private_obj, log)
             self._profiler_record("{}-midp#{}_1".format(op_info_prefix, tid))
             if error_channeldata is not None:
                 self._push_to_output_channels(error_channeldata,
@@ -388,7 +400,7 @@ class Op(object):
             # postprocess
             self._profiler_record("{}-postp#{}_0".format(op_info_prefix, tid))
             output_data, error_channeldata = self._run_postprocess(
-                parsed_data, midped_data, data_id, log)
+                parsed_data, midped_data, data_id, private_obj, log)
             self._profiler_record("{}-postp#{}_1".format(op_info_prefix, tid))
             if error_channeldata is not None:
                 self._push_to_output_channels(error_channeldata,
@@ -411,7 +423,7 @@ class RequestOp(Op):
         # PipelineService.name = "#G"
         super(RequestOp, self).__init__(
             name="#G", input_ops=[], concurrency=concurrency)
-        # load user resources
+        # init op
         try:
             self.init_op()
         except Exception as e:
@@ -436,7 +448,7 @@ class ResponseOp(Op):
     def __init__(self, input_ops, concurrency=1):
         super(ResponseOp, self).__init__(
             name="#R", input_ops=input_ops, concurrency=concurrency)
-        # load user resources
+        # init op
         try:
             self.init_op()
         except Exception as e: