:getPopupContainer="trigger => trigger.parentElement" //搞定
<a-select v-model="monitorInfo.position" style="width: 200px" :getPopupContainer="trigger => trigger.parentElement">
<a-select-option v-for="(v, k) in searchPosition" :key="k" :value="k">
{{ v }}
</a-select-option>
</a-select>