diff --git a/src/client/src/tscUtil.c b/src/client/src/tscUtil.c
index 1073eec6ea7de122d311620f058abfcf97f09bdb..dbd3f464eaf457b9002bb5cd6af6bfd88e5cfbc1 100644
--- a/src/client/src/tscUtil.c
+++ b/src/client/src/tscUtil.c
@@ -87,6 +87,7 @@ void tscGetMetricMetaCacheKey(SQueryInfo* pQueryInfo, char* str, uint64_t uid) {
     MD5Update(&ctx, (uint8_t*)tmp, keyLen);
     char* pStr = base64_encode(ctx.digest, tListLen(ctx.digest));
     strcpy(str, pStr);
+    free(pStr);
   }
 
   free(tmp);