diff --git a/src/input/props.ts b/src/input/props.ts
index a39df2a4a2..d2a56065ca 100644
--- a/src/input/props.ts
+++ b/src/input/props.ts
@@ -114,16 +114,16 @@ export default {
   /** 输入框的值 */
   value: {
     type: String as PropType<TdInputProps['value']>,
-    default: undefined,
+    default: undefined as TdInputProps['value'],
   },
   modelValue: {
     type: String as PropType<TdInputProps['value']>,
-    default: undefined,
+    default: undefined as TdInputProps['value'],
   },
   /** 输入框的值，非受控属性 */
   defaultValue: {
     type: String as PropType<TdInputProps['defaultValue']>,
-    default: '',
+    default: '' as TdInputProps['defaultValue'],
   },
   /** 失去焦点时触发 */
   onBlur: Function as PropType<TdInputProps['onBlur']>,