要的效果如下

需要合并 show weak 及 Siginin这三列

上代码

<template>
  <Table
    :columns="columns"
    :span-method="handleSpan"
    :data="data"
    border
    size="small"
    ref="table"
  ></Table>
</template>
<script>
export default {
  data() {
    return {
      columns: [
        {
          title: "Name",
          key: "name",
          fixed: "left",
          width: 200,
          children: [
            {
              title: "Show",
              key: "show",
              width: 150,
              sortable: true,
              fixed: "left",
            },
            {
              title: "Weak",
              key: "weak",
              width: 150,
              sortable: true,
              fixed: "left",
            },
            {
              title: "Signin",
              key: "signin",
              width: 150,
              sortable: true,
              fixed: "left",
            },
          ],
        },

        {
          title: "Click",
          key: "click",
          width: 150,
          sortable: true,
        },
        {
          title: "Active",
          key: "active",
          width: 150,
          sortable: true,
        },
        {
          title: "7, retained",
          key: "day7",
          width: 150,
          sortable: true,
        },
        {
          title: "30, retained",
          key: "day30",
          width: 150,
          sortable: true,
        },
        {
          title: "The next day left",
          key: "tomorrow",
          width: 150,
          sortable: true,
        },
        {
          title: "Day Active",
          key: "day",
          width: 150,
          sortable: true,
        },
        {
          title: "Week Active",
          key: "week",
          width: 150,
          sortable: true,
        },
        {
          title: "Month Active",
          key: "month",
          width: 150,
          sortable: true,
        },
      ],
      data: [
        {
          name: "Name1",
          fav: 0,
          show: "show",
          weak: "weak",
          signin: "signin",
          click: "click",
          active: "active",
          day7: "day7",
          day30: "day30",
          tomorrow: "tomorrow",
          day: "day",
          week: "week",
          month: "month",
        },
        {
          name: "Name2",
          fav: 0,
          show: "show2",
          weak: "weak2",
          signin: "signin2",
          click: "clic2",
          active: "active2",
          day7: "day72",
          day30: "day302",
          tomorrow: "tomorrow2",
          day: "day2",
          week: "week2",
          month: "month2",
        },
        {
          name: "Name3",
          fav: 0,
          show: "show3",
          weak: "weak3",
          signin: "signin3",
          click: "click3",
          active: "active3",
          day7: "day73",
          day30: "day303",
          tomorrow: "tomorrow3",
          day: "day3",
          week: "week3",
          month: "month3",
        },
      ],
    };
  },
  methods: {
    handleSpan({ row, column, rowIndex, columnIndex }) {
      if (columnIndex ===0) {
        return [1, 3];
      }else if(columnIndex>0&&columnIndex<3){
        return [0, 0];
      } else {
        return [1, 1];
      }
    },
  },
};
</script>

主要 handleSpan 方法

• 这些ui框架的合并策略 返回 [0,0] 才会不占据位置，才不会错乱，合并[1,3]后还需要考虑 被占据位置后的单元格
• 上面代码的意思就是 columnIndex 为0时，合并第一个到第三个单元格，columnIndex大于0 并且小于3时 不占据位置 其他的还是占据 [1,1]