diff --git a/src/components/common/VnInput.vue b/src/components/common/VnInput.vue
index 9821992cbf2..474d681165c 100644
--- a/src/components/common/VnInput.vue
+++ b/src/components/common/VnInput.vue
@@ -84,7 +84,7 @@ const mixinRules = [
     ...($attrs.rules ?? []),
     (val) => {
         const maxlength = $props.maxlength;
-        if (maxlength && +val.length > maxlength)
+        if (maxlength && +val?.length > maxlength)
             return t(`maxLength`, { value: maxlength });
         const { min, max } = vnInputRef.value.$attrs;
         if (!min) return null;