<el-tree
            ref="tree"
            node-key="id"
            show-checkbox
            :data="organizationTree"
            :props="defaultProps"
            :default-expanded-keys="expandedKeys"
            :default-checked-keys="checkedKeys"
            :check-strictly="true"
            @check="handleNodeClick"
          >
          </el-tree>

      defaultProps: {
        id: 'id',
        children: 'children',
        label: 'title',
        isLeaf: (data, node) => {
          if (node.level === 2) {
            return true
          }
        },
      },

css隐藏

  ::v-deep {
    /* 设置树形最外层的背景颜色和字体颜色 */
    .is-leaf::before  {
      display:none;
    }
    }