diff --git a/src/storage/column_store/ob_co_merge_dag.cpp b/src/storage/column_store/ob_co_merge_dag.cpp
index cdf9504b5d..ee6497ecde 100644
--- a/src/storage/column_store/ob_co_merge_dag.cpp
+++ b/src/storage/column_store/ob_co_merge_dag.cpp
@@ -1140,7 +1140,7 @@ int ObCOMergeDagNet::create_co_execute_dags(share::ObIDag &schedule_dag)
     ret = OB_ERR_UNEXPECTED;
     LOG_WARN("merge ctx is null or schema invalid", K(ret), KPC(co_merge_ctx_));
     SET_DAG_LOCATION(&schedule_dag);
-  } else if (OB_FAIL(choose_merge_batch_size(*co_merge_ctx_))) {
+  } else if (OB_FAIL(choose_merge_batch_size(co_merge_ctx_->array_count_))) {
     LOG_WARN("failed to choose merge batch size", K(ret));
   } else if (OB_FAIL(inner_create_and_schedule_dags(&schedule_dag))) {
     LOG_WARN("failed to create and schedule dags", K(ret));
@@ -1149,14 +1149,13 @@ int ObCOMergeDagNet::create_co_execute_dags(share::ObIDag &schedule_dag)
   return ret;
 }
 
-int ObCOMergeDagNet::choose_merge_batch_size(ObCOTabletMergeCtx &co_ctx)
+int ObCOMergeDagNet::choose_merge_batch_size(const int64_t column_group_cnt)
 {
   int ret = OB_SUCCESS;
-  const int64_t column_group_cnt = co_ctx.array_count_;
 
   if (OB_UNLIKELY(column_group_cnt <= 0)) {
     ret = OB_ERR_UNEXPECTED;
-    LOG_WARN("get unexpected count", K(ret), K(column_group_cnt), K(co_ctx));
+    LOG_WARN("get unexpected count", K(ret), K(column_group_cnt));
   } else if (column_group_cnt < ObCOTabletMergeCtx::DEFAULT_CG_MERGE_BATCH_SIZE * 2) {
     merge_batch_size_ = column_group_cnt;
   } else {
@@ -1211,13 +1210,15 @@ void ObCOMergeDagNet::try_update_merge_batch_size(const int64_t column_group_cnt
   int64_t batch_mem_allow_per_thread = MAX(mem_allow_used / merge_thread - ObCompactionEstimator::MAJOR_MEM_PER_THREAD, 0);
   int64_t mem_allow_batch_size = MAX(batch_mem_allow_per_thread / ObCompactionEstimator::CO_MAJOR_CG_BASE_MEM, 1);
 
-  if (mem_allow_batch_size >= column_group_cnt) {
-    merge_batch_size_ = column_group_cnt;
-  } else if (mem_allow_batch_size > merge_batch_size_) {
-    merge_batch_size_ = mem_allow_batch_size;
-  } else {
-    //TODO(@DanLing) use default batch size now, we need more experiment about mem stat to dec batch size
+  if (mem_allow_batch_size > merge_batch_size_ * 2) {
+    merge_batch_size_ = MIN(merge_batch_size_ * 2, column_group_cnt);
+  } else if (OB_TMP_FAIL(choose_merge_batch_size(column_group_cnt))) {
+    merge_batch_size_ = ObCOTabletMergeCtx::DEFAULT_CG_MERGE_BATCH_SIZE;
+    LOG_WARN_RET(tmp_ret, "failed to choose merge batch size, use default batch size", K(column_group_cnt), K(merge_batch_size_));
   }
+
+  FLOG_INFO("[ADAPTIVE_SCHED] update co merge batch size", K(merge_thread),
+      K(mem_allow_used), K(batch_mem_allow_per_thread), K(mem_allow_batch_size), K(merge_batch_size_));
 }
 
 int ObCOMergeDagNet::inner_create_and_schedule_dags(ObIDag *parent_dag)
diff --git a/src/storage/column_store/ob_co_merge_dag.h b/src/storage/column_store/ob_co_merge_dag.h
index b122b8b0fd..4dda4ec701 100644
--- a/src/storage/column_store/ob_co_merge_dag.h
+++ b/src/storage/column_store/ob_co_merge_dag.h
@@ -318,7 +318,7 @@ private:
       const int64_t max_cg_idx,
       ObCOMergeBatchExeDag *&dag,
       const bool add_scheduler_flag = true);
-  int choose_merge_batch_size(ObCOTabletMergeCtx &co_ctx);
+  int choose_merge_batch_size(const int64_t column_group_cnt);
   int inner_schedule_finish_dag(ObIDag *parent_dag = nullptr);
   void try_update_merge_batch_size(const int64_t column_group_cnt);
   int inner_create_and_schedule_dags(ObIDag *parent_dag = nullptr);