关于lazyload无法加载第二级的问题

let that = this;
props: {
  lazy: true,
  lazyLoad (node, resolve) {
    setTimeout(()=>{
      let param = {
         parent: node.level == 0?‘‘:node.value
      }
      that.axios.get(‘**************‘, {params: param}).then(res=>{
        if(res.data.flag == ‘S‘){
          const nodes = res.data.data.map(item =>{
            return {
              value: item.strKey,
              label: item.value,
              leaf: node.level >= 1
            }
          })
          resolve(nodes)
        }else{
       　　that.$message.error(res.data.message)
        }
      })
     },200)
   }
 },