<el-tree

                :data="authData"

                show-checkbox

                :check-strictly="true"

                :check-on-click-node="true"

                node-key="_id"

                ref="yourTreeId"

                @check-change="getCheckedKeys"

                highlight-current

                :props="defaultProps"

                :filter-node-method="filterAuthData"

                @check="handleCheck"

              >

              </el-tree>

 methods: {

    //点击父级展开所有子菜单

    handleCheck(data){

      let expandedData = this.$refs.yourTreeId.store.nodesMap;

       expandedData[data._id].expanded = true;

       if(data?.children?.length){ //有多少层子集，循环多少次

          data?.children?.map(obj=>{

            expandedData[obj._id].expanded = true;

            if(obj?.children?.length){

              obj.children.map(obj2=>{

                expandedData[obj2._id].expanded = true;

              })

            }

          })

       }

    },

}