popper-class可以修改其样式。

写法：

<el-popover v-if="showNav === false" popper-class="el-popover-self">
  <template #reference>
    <el-icon class="recorder_open">
      <DArrowLeft style="color: #ffb814"/>
    </el-icon>
  </template>
  <div>
    <el-button class="text-ver">上传记录</el-button>
    <el-button class="text-ver">安装记录</el-button>
  </div>
</el-popover>

<style lang="less">
.el-popover.el-popper.el-popover-self{
  min-width: 20px!important;
  width: 20px!important;
  padding: 0;
}
</style>