子组件：

<script setup lang="ts">
//父组件v-model默认绑定modelValue属性（建议）。如要更换属性名将v-model="searchText" 修改为v-model：newValue="searchText" (newValue为新名称)，修改后子组件也要相应修改，此时子组件不能更新父组件的值。
const prop = defineProps(['modelValue']) 
const emits = defineEmits(['update:modelValue'])

const handleChange = (e: string) => {
  emits('update:modelValue', e)
}

</script>

<template>
  <input v-model="modelValue"  @update:model-value="handleChange"/>
</template>

父组件：

<script lang="ts" setup>
import { defineComponent, ref } from 'vue'
import vModel from '../../components/vModel/index.vue'

const searchText = ref({ name: 'kkkk' })
</script>

<template>
  <vModel v-model="searchText.name" />
  <vModel :modelValue="searchText.name" @update:modelValue="(newValue) => (searchText.name = newValue)" />
  <h1>------------{{ searchText.name }} -------------</h1>
</template>