diff --git a/tools/shell/src/shellEngine.c b/tools/shell/src/shellEngine.c
index 115abdcd36..e8a5b04178 100644
--- a/tools/shell/src/shellEngine.c
+++ b/tools/shell/src/shellEngine.c
@@ -1091,7 +1091,12 @@ void shellSourceFile(const char *file) {
 
   char *line = taosMemoryMalloc(TSDB_MAX_ALLOWED_SQL_LEN + 1);
   while ((read_len = taosGetsFile(pFile, TSDB_MAX_ALLOWED_SQL_LEN, line)) != -1) {
-    if (read_len >= TSDB_MAX_ALLOWED_SQL_LEN) continue;
+    if ( cmd_len + read_len >= TSDB_MAX_ALLOWED_SQL_LEN) {
+      printf("read command line too long over 1M, ignore this line. cmd_len = %d read_len=%d \n", (int32_t)cmd_len, read_len);
+      cmd_len = 0;
+      memset(line, 0, TSDB_MAX_ALLOWED_SQL_LEN + 1);
+      continue;
+    }
     line[--read_len] = '\0';
 
     if (read_len == 0 || shellIsCommentLine(line)) {  // line starts with #