diff --git a/ge/graph/manager/graph_manager.cc b/ge/graph/manager/graph_manager.cc
index 3f07b47e..727d1490 100755
--- a/ge/graph/manager/graph_manager.cc
+++ b/ge/graph/manager/graph_manager.cc
@@ -693,10 +693,16 @@ Status GraphManager::PreRun(const GraphNodePtr &graph_node, const std::vector<Ge
     }
   }
 
-  ret = PreRunOptimizeSubGraph(graph_node, compute_graph, session_id);
-  if (ret != SUCCESS) {
-    GELOGE(ret, "Run PreRunOptimizeSubGraph failed for graph:%s.", compute_graph->GetName().c_str());
-    return ret;
+
+  // BUILD_MODE_TUNING with BUILD_STEP_AFTER_MERGE no need PreRunOptimizeSubGraph.
+  bool run_optimize_subgraph =
+      !((options_.build_mode == BUILD_MODE_TUNING) && (options_.build_step == BUILD_STEP_AFTER_MERGE));
+  if (run_optimize_subgraph) {
+    Status ret = PreRunOptimizeSubGraph(graph_node, compute_graph, session_id);
+    if (ret != SUCCESS) {
+      GELOGE(ret, "Run PreRunOptimizeSubGraph failed for graph:%s.", compute_graph->GetName().c_str());
+      return ret;
+    }
   }
 
   /// 1. BUILD_MODE_TUNING with BUILD_STEP_BEFORE_UB_MATCH no need PreRunAfterOptimizeSubGraph;
diff --git a/ge/graph/optimize/graph_optimize.cc b/ge/graph/optimize/graph_optimize.cc
index d0931e24..ebf09afb 100644
--- a/ge/graph/optimize/graph_optimize.cc
+++ b/ge/graph/optimize/graph_optimize.cc
@@ -101,8 +101,7 @@ Status GraphOptimize::OptimizeSubGraph(ComputeGraphPtr &compute_graph, const std
       return SUCCESS;
     }
 
-    if (build_mode_ == BUILD_MODE_TUNING &&
-      (build_step_ == BUILD_STEP_AFTER_UB_MATCH || build_step_ == BUILD_STEP_AFTER_MERGE)) {
+    if (build_mode_ == BUILD_MODE_TUNING && build_step_ == BUILD_STEP_AFTER_UB_MATCH) {
       for (auto iter = graph_optimizer.begin(); iter != graph_optimizer.end(); ++iter) {
         Status ret = (*iter)->OptimizeFusedGraphAfterGraphSlice(*(compute_graph));
         if (ret != SUCCESS) {