出问题的代码：

{
      path: '/',
      name: 'Home',
      component: Home,
      children: [
        {
          path: 'welcome',
          name: 'welcome',
          meta: {
            name: '主页'
          },
          component: welcome
        },
        {
          path: 'cdmanage',
          name: 'cdmanage',
          meta: {
            name: '课程设计管理'
          },
          children: [
            {
              path: 'importstu',
              name: 'ImportStudent',
              component: ImportStudent,
              meta: {
                name: '导入学生信息'
              }
            }
          ]
        }
      ]
    }

正常的代码：

{
      path: '/',
      name: 'Home',
      component: Home,
      children: [
        {
          path: 'welcome',
          name: 'welcome',
          meta: {
            name: '主页'
          },
          component: welcome
        },
        {
          path: 'cdmanage',
          name: 'cdmanage',
          meta: {
            name: '课程设计管理'
          },
          component: ForRouter,//修改点
          children: [
            {
              path: 'importstu',
              name: 'ImportStudent',
              component: ImportStudent,
              meta: {
                name: '导入学生信息'
              }
            }
          ]
        }
      ]
    }

感觉是页面只能匹配一层路由，如果需要匹配下一级那么需要嵌套<router-view/>，为此，我编写一个组件给了二级路由，不给就不渲染三级路由

<template>
    <router-view/>
</template>

<script>
    export default {
        name: "ForRouter"
    }
</script>

<style scoped>

</style>