使用三目运算符替代

<transition name='el-fade-in-linear' appear={true}>
  <span class='e-filter-btn'>
    <i class={[
      'e-filter-tag',
      _this.filterLoads.some((fl) => fl === colKey)? "el-icon-loading" : '',
      !_this.filterLoads.some((fl) => fl === colKey)? "el-icon-arrow-down" : ''
    ]}>
    </i>
  </span>
</transition>