import mirror from 'xx/mirror'
 export default {
  components:{
   mirror
  },
  data(){
   return {
    width:300,
    picList:[
      xxxxxx,
      xxxxxx
    ],
   }
  }
 }

<mirror :width="width" :picList="picList" />  

<template>
 <div class="mirror">
   <div class="wrap" :style="{width:width+'px',height:width+'px'}" >
    <div ref="truth" :style="{width:'100%',height:'100%'}" @mousemove="move" @mouseenter="showMagnify" @mouseleave="hideMagnify">
    <div class="mask" ref="mask" v-show = "showMask" :style="{width:width/2+'px',height:width/2+'px',left:maskPosition.x+'px',top:maskPosition.y+'px'}"></div>
    <img :src="picList[picIndex]" draggable="false"/>
    </div>
    <div class="virtual" ref="virtual" v-if = "isShowVirtual" :style="{width:width+'px',height:width+'px'}" >
      <div class="big" ref = "bigPic" :style="{position:'absolute',width:2*width+'px',height:2*width+'px',backgroundSize:'100% 100%',backgroundImage:`url(${picList[picIndex]})`,left:percent.x, top:percent.y}" >
      </div>
    </div>
   </div>
   <ul class="picList" :style="{width:width+'px'}">
     <li v-for = "(item,index) in picList" :class="{now:index==picIndex}" :data-index="index" :key ="item" @mouseenter="changeIndex">
      <img :src ="item" />
     </li>
   </ul>
 </div>
</template>

 export default {
   props:['width','picList'],//寬度是用來給放大鏡的
   data(){
    return {
     picIndex:0,
     isShowVirtual:false,
     showMask:false,
     maskPosition:{},
     percent:{},
    }
   },
   methods:{
    computedOffset(obj,prop){ //計(jì)算元素到body的絕對(duì)位置
    if(obj==document.body || obj.offsetParent == document.body){
     return parseInt(obj[prop])
    }
    return parseInt(obj[prop])+this.computedOffset(obj.offsetParent,prop)
  },
    changeIndex(e){
     this.picIndex = e.target.dataset.index
    },
    showMagnify(e){
     this.showMask=true;
     this.isShowVirtual = true;
    },
    hideMagnify(){
     this.isShowVirtual=false;
     this.showMask=false
    },
    computePosition(e){
      let x = e.pageX,y = e.pageY;
      let mask = this.$refs.mask;
      let truth = this.$refs.truth;
      let virtual = this.$refs.virtual;
      let bigPic = this.$refs.bigPic;
      x = x-this.computedOffset(truth,'offsetLeft') -mask.offsetWidth/2;
      y = y-this.computedOffset(truth,'offsetTop')- mask.offsetHeight/2;
     if(x<=0) {
       x=0
      }else if(x>truth.offsetWidth - mask.offsetWidth){
       x = truth.offsetWidth/2
      }
      if(y<=0){
       y=0;
      }
      else if(y>truth.offsetHeight - mask.offsetHeight){
       y = truth.offsetHeight/2
      }

      this.maskPosition = {
       x,y
      }
      //計(jì)算比例
      this.percent={
       x:-x/(truth.offsetWidth-mask.offsetWidth)*(bigPic.offsetWidth - virtual.offsetWidth)+'px',
       y:-y/(truth.offsetHeight-mask.offsetHeight)*(bigPic.offsetHeight - virtual.offsetHeight)+'px'
      }
    },
    move(e){
     this.computePosition(e)
    }
  }
  }

<style lang="less" scoped>
.now{
 border-color: cyan !important;
}
 .mirror{
  width:100%;
  .wrap{
   user-select: none;
   margin-bottom: 20px;
   position: relative;
   background-color: #fff;
   border:1px solid gray;
   box-sizing:border-box;
     cursor: pointer;
    img{
     width:100%;
     height:100%;
    }
    .virtual{
     overflow:hidden;
     width:100%;
     height:100%;
     position:absolute;
     left:calc(100% + 10px);
     top:0;
     background-repeat:no-repeat
    }
    .mask{
     position: absolute;
     background-image: url('https://img-tmdetail.alicdn.com/tps/i4/T12pdtXaldXXXXXXXX-2-2.png');
     background-repeat:repeat;
     cursor: move;
    }
  }
  .picList{
   width:100%;
   display: flex;
   justify-content: space-between;
   flex-wrap:wrap;
   li{
    width:50px;
    height:50px;
    margin:5px;
    border:1px solid transparent;
    box-sizing: border-box;
    img{
     width:100%;
     height:100%
    }
   }
  }
  .picList:after{
   content:"";
   flex:auto;
  }
 }
</style>