diff --git a/packages/fineui/src/core/func/alias.js b/packages/fineui/src/core/func/alias.js
index 9a8d6dc37..049797832 100644
--- a/packages/fineui/src/core/func/alias.js
+++ b/packages/fineui/src/core/func/alias.js
@@ -337,7 +337,7 @@ function _dealWithLeft(tleft, fleft) {
             newstr = "";
             let n = res.length - 1 - combo;
             for (; n >= 0; n = n - combo) {
-                newstr = `${res.substring(n, combo)},${newstr}`;
+                newstr = `${res.substring(n, n + combo)},${newstr}`;
             }
             const lres = res.substring(0, n + combo);
             if (!isEmpty(lres)) {