diff --git a/src/sql/engine/expr/ob_expr_repeat.cpp b/src/sql/engine/expr/ob_expr_repeat.cpp
index 66d126f138..1fda797e82 100644
--- a/src/sql/engine/expr/ob_expr_repeat.cpp
+++ b/src/sql/engine/expr/ob_expr_repeat.cpp
@@ -46,19 +46,21 @@ int ObExprRepeat::calc_result_type2(ObExprResType &type,
                                     ObExprTypeCtx &type_ctx) const
 {
   int ret = OB_SUCCESS;
-  if (!ob_is_text_tc(text.get_type())) {
+  if (!ob_is_text_tc(text.get_type()) && !text.is_null()) {
     text.set_calc_type(common::ObVarcharType);
   }
-  count.set_calc_type(common::ObIntType);
+  if (!count.is_null()) {
+    count.set_calc_type(common::ObIntType);
+  }
   // Set cast mode for %count parameter, truncate string to integer.
   type_ctx.set_cast_mode(type_ctx.get_cast_mode() | CM_STRING_INTEGER_TRUNC);
   // repeat is mysql only epxr.
   CK(lib::is_mysql_mode());
   if (OB_SUCC(ret)) {
     ObObjType res_type = ObMaxType;
-    if (text.is_null() || count.is_null()) {
+    if (text.is_null() && !count.is_null()) {
       res_type = ObVarcharType;
-    } else if (count.is_literal()) {
+    } else if (count.is_literal() && !count.is_null()) {
       const ObObj &obj = count.get_param();
       ObArenaAllocator alloc(ObModIds::OB_SQL_RES_TYPE);
       const ObDataTypeCastParams dtc_params =
diff --git a/tools/deploy/mysql_test/test_suite/static_engine/r/mysql/expr_trim.result b/tools/deploy/mysql_test/test_suite/static_engine/r/mysql/expr_trim.result
index 781d25195c..a87b865fde 100644
--- a/tools/deploy/mysql_test/test_suite/static_engine/r/mysql/expr_trim.result
+++ b/tools/deploy/mysql_test/test_suite/static_engine/r/mysql/expr_trim.result
@@ -187,3 +187,9 @@ select collation(TRIM( BOTH _binary'a' FROM _gbk'abc' )) ;
 | gbk_chinese_ci                                    |
 +---------------------------------------------------+
 
+select TRIM(LEADING 'a' FROM TRIM(SUBSTR(REPEAT(NULL, 4 + 1), 1, LEAST(146, 20))));
++-----------------------------------------------------------------------------+
+| TRIM(LEADING 'a' FROM TRIM(SUBSTR(REPEAT(NULL, 4 + 1), 1, LEAST(146, 20)))) |
++-----------------------------------------------------------------------------+
+| NULL                                                                        |
++-----------------------------------------------------------------------------+
diff --git a/tools/deploy/mysql_test/test_suite/static_engine/t/expr_trim.test b/tools/deploy/mysql_test/test_suite/static_engine/t/expr_trim.test
index 3933a03d6a..2f1dd3b029 100644
--- a/tools/deploy/mysql_test/test_suite/static_engine/t/expr_trim.test
+++ b/tools/deploy/mysql_test/test_suite/static_engine/t/expr_trim.test
@@ -68,5 +68,7 @@ select SUBSTRING( TRIM( BOTH CONVERT( 'a', BINARY( 0 ) ) FROM '+-Ã÷﹢ï
 select collation(TRIM( BOTH _binary'a' FROM '+-Ã÷﹢﹣±/= â¥â' )) ;
 select collation(TRIM( BOTH _binary'a' FROM _gbk'abc' )) ;
 
+select TRIM(LEADING 'a' FROM TRIM(SUBSTR(REPEAT(NULL, 4 + 1), 1, LEAST(146, 20))));
+
 connection syscon;
 --sleep 2