const filePath = `${ wx.env.USER_DATA_PATH}/${projectName}.xls`;

        wx.downloadFile({
      url: "http://192.168.100.33:8096/devled" + "/api/project/exportAioResult?myNo=" + id,
      header: {
        "Authorization": userInfo ? JSON.parse(userInfo).token : "eyJhbGciOiJIUzUxVs_C0x1_r_u1nTY6gQPJYPclBh-Mg"
       },
      filePath: filePath,
      responseType: "arraybuffer", //注意这里的responseType
      success: function (res) {
        console.log(res)
        wx.openDocument({
          filePath: res.filePath,
          fileType: 'xls',
          success: function () {
            console.log('打开文档成功')
          },
          fail: function () {
            console.log('打开失败');
          }
        })
      }
    })

结果

点是可以在PC上打开，手机打不开