diff --git a/ge/graph/passes/merge_pass.cc b/ge/graph/passes/merge_pass.cc
index d032ac57..80394e7a 100644
--- a/ge/graph/passes/merge_pass.cc
+++ b/ge/graph/passes/merge_pass.cc
@@ -48,7 +48,7 @@ Status MergePass::Run(NodePtr &node) {
     return PARAM_INVALID;
   }
 
-  const auto in_data_nodes = node->GetInDataNodes();
+  const auto &in_data_nodes = node->GetInDataNodes();
   switch (in_data_nodes.size()) {
     case 0: {
       /// Case A: input_count = 0, the output of merge node is inactive as well