data() {
  return {
  isShow: '',
  activeName:'second'
  }
 },

<template>
  <div class="tabZujian">
    <el-tabs v-model="activeName">
      <el-tab-pane label="tab1" name="first" :key="'first'">
        <child1></child1>
      </el-tab-pane>
  
      <el-tab-pane label="tab2" name="second" :key="'second'">
        <child2></child2>  
      </el-tab-pane>
    </el-tabs>
    
  </div>
</template>
 
<script>
import tabZujianChild1 from '@/tabComponents/tabZujianChild1'
import tabZujianChild2 from '@/tabComponents/tabZujianChild2'
export default {
  name: 'tabZujian',
  components:{
    child1:tabZujianChild1,
    child2:tabZujianChild2
  },
  data() {
    return {
      //默认第一个选项卡
      activeName: "first",
    }
  },
  mounted(){
    
  }
}
</script>

<template>
  <div class="child1">
    我是第一个自组件
  </div>
</template>
<script>
  export default {
   name: 'child1',
   mounted(){
     console.log("tab1组件")
   }
  }
</script>

<template>
  <div class="child2">
    我是第二个子组件
  </div>
</template>
 
<script>
  export default {
   name: 'child1',
   mounted(){
     console.log("tab2组件")
   }
  }
</script>

<template>
  <div class="tabZujian">
    
    <el-tabs v-model="activeName" @tab-click="handleClick">
      <el-tab-pane label="tab1" name="first" :key="'first'">
        <child1 v-if="isChildUpdate1"></child1>
      </el-tab-pane>
  
      <el-tab-pane label="tab2" name="second" :key="'second'">
        <child2 v-if="isChildUpdate2"></child2>  
      </el-tab-pane>
    </el-tabs>
    
  </div>
</template>
 
<script>
import tabZujianChild1 from '@/tabComponents/tabZujianChild1'
import tabZujianChild2 from '@/tabComponents/tabZujianChild2'
export default {
  name: 'tabZujian',
  components:{
    child1:tabZujianChild1,
    child2:tabZujianChild2
  },
  data() {
    return {
      //默认第一个选项卡
      activeName: "first",
      isChildUpdate1:true,
      isChildUpdate2:false
    }
  },
  mounted(){
    
  },
  methods:{
    handleClick(tab) {
      if(tab.name == "first") {
        this.isChildUpdate1 = true;
        this.isChildUpdate2 = false;
      } else if(tab.name == "second") {
        this.isChildUpdate1 = false;
        this.isChildUpdate2 = true;
      }
    }
  }
}
</script>