diff --git a/src/storage/ddl/ob_ddl_merge_task.cpp b/src/storage/ddl/ob_ddl_merge_task.cpp
index a734dd85e8..0941129b8d 100644
--- a/src/storage/ddl/ob_ddl_merge_task.cpp
+++ b/src/storage/ddl/ob_ddl_merge_task.cpp
@@ -312,7 +312,7 @@ int ObDDLTableMergeTask::init(const ObDDLTableMergeDagParam &ddl_dag_param)
 int ObDDLTableMergeTask::process()
 {
   int ret = OB_SUCCESS;
-  int64_t MAX_DDL_SSTABLE = 128;
+  int64_t MAX_DDL_SSTABLE = ObTabletDDLKvMgr::MAX_DDL_KV_CNT_IN_STORAGE * 0.5;
 #ifdef ERRSIM
   if (0 != GCONF.errsim_max_ddl_sstable_count) {
     MAX_DDL_SSTABLE = GCONF.errsim_max_ddl_sstable_count;
diff --git a/src/storage/ddl/ob_tablet_ddl_kv_mgr.h b/src/storage/ddl/ob_tablet_ddl_kv_mgr.h
index 8efc093981..a09aed4979 100644
--- a/src/storage/ddl/ob_tablet_ddl_kv_mgr.h
+++ b/src/storage/ddl/ob_tablet_ddl_kv_mgr.h
@@ -97,8 +97,9 @@ private:
   void cleanup_unlock();
   void destroy();
   bool is_commit_success_unlock() const;
+public:
+  static const int64_t MAX_DDL_KV_CNT_IN_STORAGE = 16;
 private:
-  static const int64_t MAX_DDL_KV_CNT_IN_STORAGE = 64;
   bool is_inited_;
   share::SCN success_start_scn_;
   share::ObLSID ls_id_;