diff --git a/src/sql/ob_sql_define.h b/src/sql/ob_sql_define.h
index 8085bbb47a..c42faae550 100644
--- a/src/sql/ob_sql_define.h
+++ b/src/sql/ob_sql_define.h
@@ -499,6 +499,7 @@ enum PXParallelRule
   MANUAL_TABLE_HINT, // /*+ parallel(t1 3) */
   SESSION_FORCE_PARALLEL, // alter session force parallel query parallel 3;
   MANUAL_TABLE_DOP, // create table t1 (...) parallel 3;
+  PL_UDF_DAS_FORCE_SERIALIZE, //stmt has_pl_udf will use das, force serialize;
   MAX_OPTION
 };
 
@@ -513,6 +514,7 @@ inline const char *ob_px_parallel_rule_str(PXParallelRule px_parallel_ruel)
     "MANUAL_TABLE_HINT",
     "SESSION_FORCE_PARALLEL",
     "MANUAL_TABLE_DOP",
+    "PL_UDF_DAS_FORCE_SERIALIZE",
     "MAX_OPTION",
   };
   if (OB_LIKELY(px_parallel_ruel >= NOT_USE_PX)
diff --git a/src/sql/optimizer/ob_explain_note.h b/src/sql/optimizer/ob_explain_note.h
index 431d39f151..d9415ab46e 100644
--- a/src/sql/optimizer/ob_explain_note.h
+++ b/src/sql/optimizer/ob_explain_note.h
@@ -30,6 +30,7 @@ namespace sql
 #define PARALLEL_ENABLED_BY_TABLE_HINT "Degree of Parallelism is %ld because of hint"
 #define PARALLEL_ENABLED_BY_SESSION "Degree of Parallelism is %ld because of session"
 #define PARALLEL_ENABLED_BY_TABLE_PROPERTY "Degree of Parallelisim is %ld because of table property"
+#define PARALLEL_DISABLED_BY_PL_UDF_DAS  "Degree of Parallelisim is %ld because stmt contain pl_udf which force das scan"
 
 }
 }
diff --git a/src/sql/optimizer/ob_optimizer.cpp b/src/sql/optimizer/ob_optimizer.cpp
index ae32c46d01..497e31de93 100644
--- a/src/sql/optimizer/ob_optimizer.cpp
+++ b/src/sql/optimizer/ob_optimizer.cpp
@@ -667,6 +667,12 @@ int ObOptimizer::init_env_info(ObDMLStmt &stmt)
       ctx_.set_parallel_rule(PXParallelRule::USE_PX_DEFAULT);
       ctx_.set_parallel(ObGlobalHint::DEFAULT_PARALLEL);
     }
+    //following above rule, but if stmt contain pl_udf, force das, parallel should be 1
+    if (parallel > 1 && ctx_.has_pl_udf()) {
+      ctx_.set_parallel_rule(PXParallelRule::PL_UDF_DAS_FORCE_SERIALIZE);
+      ctx_.set_parallel(1);
+      ctx_.add_plan_note(PARALLEL_DISABLED_BY_PL_UDF_DAS, 1);
+    }
   }
 
   // init column usage info
diff --git a/src/sql/optimizer/ob_optimizer_context.h b/src/sql/optimizer/ob_optimizer_context.h
index 7602c13bb4..c7b0858d1d 100644
--- a/src/sql/optimizer/ob_optimizer_context.h
+++ b/src/sql/optimizer/ob_optimizer_context.h
@@ -225,7 +225,8 @@ ObOptimizerContext(ObSQLSessionInfo *session_info,
     return px_parallel_rule_ == MANUAL_HINT ||
         px_parallel_rule_ == MANUAL_TABLE_HINT ||
         px_parallel_rule_ == SESSION_FORCE_PARALLEL ||
-        px_parallel_rule_ == MANUAL_TABLE_DOP;
+        px_parallel_rule_ == MANUAL_TABLE_DOP ||
+        px_parallel_rule_ == PL_UDF_DAS_FORCE_SERIALIZE;
   }
   inline bool use_intra_parallel() const
   {