diff --git a/src/sql/code_generator/ob_code_generator_impl.cpp b/src/sql/code_generator/ob_code_generator_impl.cpp
index a1917756a96c779d215371b640b7416bb4ce8672..4db8f0f5c08532e55ecaacc22fe83a4656204c4f 100644
--- a/src/sql/code_generator/ob_code_generator_impl.cpp
+++ b/src/sql/code_generator/ob_code_generator_impl.cpp
@@ -7008,7 +7008,7 @@ int ObCodeGeneratorImpl::convert_table_lookup(ObLogTableLookup& op, const PhyOps
   }
 #endif
   // in any case, destroy row desc
-  if (NULL != table_scan_out_ops.at(0).second) {
+  if (table_scan_out_ops.count() > 0 && NULL != table_scan_out_ops.at(0).second) {
     ob_delete(table_scan_out_ops.at(0).second);
   }
   return ret;