将绑定的对应值设置成undefined

<a-selectv-model:value="formState.classification"option-filter-prop="children"allow-clearplaceholder="商户分类"><a-select-optionv-for="item of Object.values(Const.POINTMERCHNANDISE.TYPE_MAP)":key="item.value":value="item.value">{{ item.text }}</a-select-option></a-select>
const formState = ref({classification: undefined, // 商户分类
});