diff --git a/source/common/src/tcol.c b/source/common/src/tcol.c
index 5fb496cf14..90420b7441 100644
--- a/source/common/src/tcol.c
+++ b/source/common/src/tcol.c
@@ -271,6 +271,7 @@ bool checkColumnCompressOrSetDefault(uint8_t type, char compress[TSDB_CL_COMPRES
 }
 bool checkColumnLevel(char level[TSDB_CL_COMPRESS_OPTION_LEN]) {
   if (0 == strlen(level)) return true;
+  strtolower(level, level);
   if (1 == strlen(level)) {
     if ('h' == level[0] || 'm' == level[0] || 'l' == level[0]) return true;
   } else {