vue下的elementui轮播图自适应高度问题

<el-carousel :interval="5000" arrow="never" :height="autoHeight">
     <el-carousel-item v-for="(banner, index) in banners" :key="index">
        <a :href="banner.extra.tourl" rel="external nofollow" >
            <img :src="banner.imgurl" :title="banner.title" class="max-img">
        </a>
     </el-carousel-item>
  </el-carousel>

 getAutoHeight(){
     let _w = document.documentElement.clientWidth || document.body.clientWidth; ; 
     this.autoHeight = _w * 145 / 375 + 'px';
  }

 <div class="slide_pc">
         <el-carousel trigger="click" height="37vw" @change="loadAnimate"  :interval="5000" arrow="hover">
            <el-carousel-item v-for="(item,index) in imgurl" :key="index">
              <figure>
                <img :src="item" style="width:100%;height: auto;"/>
              </figure>
            </el-carousel-item>
          </el-carousel>
          <!-- <slider-show :slides="sliders" :inv="invTime"></slider-show> -->
    </div>

width: 100%; height: auto;