diff --git a/shards/mishards/service_handler.py b/shards/mishards/service_handler.py
index 620f6213de..640ae61ba8 100644
--- a/shards/mishards/service_handler.py
+++ b/shards/mishards/service_handler.py
@@ -34,13 +34,14 @@ class ServiceHandler(milvus_pb2_grpc.MilvusServiceServicer):
             return source_ids, source_diss
         if diss[k - 1] <= source_diss[0]:
             return ids, diss
-        
-        diss_t = enumerate(source_diss.extend(diss))
+
+        source_diss.extend(diss)
+        diss_t = enumerate(source_diss)
         diss_m_rst = sorted(diss_t, key=lambda x: x[1])[:k]
         diss_m_out = [id_ for _, id_ in diss_m_rst]
 
-        id_t = source_ids.extend(ids)
-        id_m_out = [id_t[i] for i, _ in diss_m_rst]
+        source_ids.extend(ids)
+        id_m_out = [source_ids[i] for i, _ in diss_m_rst]
 
         return id_m_out, diss_m_out
 
@@ -50,8 +51,6 @@ class ServiceHandler(milvus_pb2_grpc.MilvusServiceServicer):
         if not files_n_topk_results:
             return status, []
 
-        # request_results = defaultdict(list)
-        # row_num = files_n_topk_results[0].row_num
         merge_id_results = []
         merge_dis_results = []
 
@@ -64,6 +63,7 @@ class ServiceHandler(milvus_pb2_grpc.MilvusServiceServicer):
             row_num = files_collection.row_num
             ids = files_collection.ids
             diss = files_collection.distances  # distance collections
+            # TODO: batch_len is equal to topk
             batch_len = len(ids) // row_num
 
             for row_index in range(row_num):
@@ -77,28 +77,16 @@ class ServiceHandler(milvus_pb2_grpc.MilvusServiceServicer):
                     merge_id_results.append(id_batch)
                     merge_dis_results.append(dis_batch)
                 else:
-                    merge_id_results[row_index].extend(ids[row_index * batch_len, (row_index + 1) * batch_len])
-                    merge_dis_results[row_index].extend(diss[row_index * batch_len, (row_index + 1) * batch_len])
-                    # _reduce(_ids, _diss, k, reverse)
                     merge_id_results[row_index], merge_dis_results[row_index] = \
                         self._reduce(merge_id_results[row_index], id_batch,
                                      merge_dis_results[row_index], dis_batch,
                                      batch_len,
                                      reverse)
 
-            # for request_pos, each_request_results in enumerate(
-            #         files_collection.topk_query_result):
-            #     request_results[request_pos].extend(
-            #         each_request_results.query_result_arrays)
-            #     request_results[request_pos] = sorted(
-            #         request_results[request_pos],
-            #         key=lambda x: x.distance,
-            #         reverse=reverse)[:topk]
 
         calc_time = time.time() - calc_time
         logger.info('Merge takes {}'.format(calc_time))
 
-        # results = sorted(request_results.items())
         id_mrege_list = []
         dis_mrege_list = []
 
@@ -106,10 +94,6 @@ class ServiceHandler(milvus_pb2_grpc.MilvusServiceServicer):
             id_mrege_list.extend(id_results)
             dis_mrege_list.extend(dis_results)
 
-        # for result in results:
-        #     query_result = TopKQueryResult(query_result_arrays=result[1])
-        #     topk_query_result.append(query_result)
-
         return status, id_mrege_list, dis_mrege_list
 
     def _do_query(self,