实现效果:

直接上代码:

<template>
    <div>
        <div class="tops">
            <el-tree  :default-expanded-keys="['1']" ref="myTree" :data="data" :props="defaultProps" @node-click="handleNodeClick" highlight-current node-key="value">
                <span class="custom-tree-node" slot-scope="{ node, data }">
                    <i v-if="node.level == 1" class="father" />
                    <i v-else-if="node.level == 2" class="son" />
                    <i v-else-if="node.level == 3" />
                    {{ data.label }}
                </span>
            </el-tree>
        </div>
    </div>
</template>

<script>
let that=this
      export default {
        data() {
        return {
            data: [
                        {
                        label: '1号生活区',
                        value:'1',
                        isShow:true,//当前折叠部分是否打开
                        children: [
                                {
                                label: '1号楼',
                                value:'1-1',
                                },
                                {
                                    label: '2号楼',
                                    value:'1-2',
                                },
                                {
                                    label: '3号楼',
                                    value:'1-3',
                                },
                                {
                                    label: '4号楼',
                                    value:'1-4',
                                },
                        ]
                        }, 
                        {
                        label: '2号生活区',
                        value:'2',
                        isShow:false,
                        children: [
                            {
                                label: '1号楼',
                                value:'2-1',
                                },
                                {
                                    label: '2号楼',
                                    value:'2-2'
                                },
                        ]
                        }, 
                        {
                        label: '3号生活区',
                        value:'3',
                        isShow:false,
                        children: [
                                {
                                label: '1号楼',
                                value:'3-1',
                                },
                                {
                                    label: '2号楼',
                                    value:'3-2',
                                },
                                {
                                    label: '3号楼',
                                    value:'3-3',
                                },
                        ]
                        },
                        {
                        label: '4号生活区',
                        value:'4',
                        isShow:false,
                        children: [
                                {
                                label: '1号楼',
                                value:'4-1',
                                },
                                {
                                    label: '2号楼',
                                    value:'4-2',
                                },
                                {
                                    label: '3号楼',
                                    value:'4-3',
                                },
                        ]
                        }
                    ],
            defaultProps: {
            children: 'children',
            label: 'label'
            },
            value1: '',
            value2:'',
        
        };

        },
        methods: {
        handleNodeClick(data) {
            this.$emit('treesVal',data)
        }, 
        },
        mounted () {
            this.$nextTick(function () {
            this.$nextTick(() => {
                // myTree 数组件的ref  默认让第一项高亮 
                // data是树组件对应的数据
                // 通过data中的第一项的id找到对应的节点，然后把这个节点设置为高亮
                this.$refs.myTree.setCurrentKey(this.data[0].value)
            });
        });
        },
  };
</script>

<style lang="scss" scoped>
@import '@/style/util.scss';
.tops{
    width: vw(260);
    height: 100%;
    background-color: #fff;
    margin: 0 auto;
    padding:0 vw(8);
    box-shadow: 0 vw(2) vw(10) 0 rgba(0,5,10,0.1);
     //设置行高
    >>>.el-tree-node__content{
        position: relative;
        height: vh(52);
        box-sizing: border-box;
    }
   //小三角的位置 以及默认时候的位置
    >>>.el-tree-node__expand-icon{
        webkit-transform:rotate(-90deg);
        transform: rotate(-90deg);
        user-select: none;
        position: absolute;
        top: vh(8);
        right: 0;
    } 
  //小三角点击展开时候旋转的角度
    >>>.el-tree-node__expand-icon.expanded{
        webkit-transform:rotate(90deg);
        transform: rotate(90deg);
        user-select: none;
    }
  //插入的父级的图标的样式  
    .father {
        background: url('../assets/img/flower-wxz.png') no-repeat;
        width: vw(18);
        height: vw(18);
        display: inline-block;
        background-size: 100% 100%;
        // margin-left: vw(20) !important;
        margin: 0 vw(8) 0 vw(20) !important;
    }
    //插入的自己的图标样式
    .son {
        width: vw(4);
        height: vw(4);
        border-radius: 50%;
        background: #666666;
        display: inline-block;
        background-size: 100% 100%;
        margin: 0 vw(8) vh(3) vw(35) !important;
    }

    //有子节点 且未展开 小三角
    .el-tree /deep/ .el-icon-caret-right:before {
        color: #858585;
        font-weight: 600;
    }
    //有子节点 且已展开 小三角
    .el-tree /deep/ .el-tree-node__expand-icon.expanded.el-icon-caret-right:before {
    color: #4F8BE2 !important;
    font-weight: 600;
    }
    //没有子节点 小三角
    .el-tree /deep/.el-tree-node__expand-icon.is-leaf::before {
    content: "";
    display: block;
    font-weight: 600;
    width: vw(12);
    height: vw(12);
    font-size: vw(16);
    background-size: 100% 100%;
    }
    >>>.el-tree-node__content .custom-tree-node{
        font-family: 'pfm';
        font-size: vw(16);
        color: #4e4e4e;
        line-height: vh(52);
        font-weight: 500;
        user-select: none;
    }
    >>>.el-tree-node__children .el-tree-node .el-tree-node__content .custom-tree-node{
        font-family: 'pf';
        font-size: vw(16);
        color: #666666;
        line-height: vh(52);
        font-weight: 500;
        user-select: none;
    }
    >>>.el-tree-node__content {
        border-left: vw(4) solid  transparent;
    }
    //选中颜色
    /deep/ .el-tree--highlight-current .el-tree-node.is-current > .el-tree-node__content {
            background: #ECF4FF !important;
            border-left: vw(4) solid  #4F8BE2;
            span{
                color: #4F8BE2;
                font-weight: 600;
            }
            .father {
                background: url('../assets/img/flower-xz.png') no-repeat;
                width: vw(18);
                height: vw(18);
                display: inline-block;
                background-size: 100% 100%;
                // margin-left: vw(20) !important;
                margin: vh(-3) vw(8) 0 vw(20) !important;
            
                }
                .son {
                    width: vw(4);
                    height: vw(4);
                    border-radius: 50%;
                    background:  #4F8BE2;
                    display: inline-block;
                    background-size: 100% 100%;
                    margin: 0 vw(8) vh(3) vw(35) !important;
                }    
        
    }
   
}
</style>