currData初始化为对象，执行Array.prototype.push.apply(currData, jsonObj.object)使其成为了伪数组(key值为0，1，2..索引并有length属性的对象)，可以通过Array.prototype.slice.call(currData)转成数组。

  loadSignReplyInfo: function() {

var _this=this  

    wx.request({

      url:""

      success: function(res) {

        console.log("reply");

        console.log(res);

        //var jsonObj = JSON.parse(res.data);

        var jsonObj = res.data;

        if (jsonObj.statusCode == 200) {

          var currData = {};

          if (_this.data.pageNum == 1) {

            currData = jsonObj.object;

          } else if (_this.data.pageNum != 1) {

            currData = _this.data.signReplyList

            // currData = currData.concat(jsonObj.object);

            Array.prototype.push.apply(currData, jsonObj.object)

          }

          console.log("currData")

          console.log(currData)

          _this.setData({

            signReplyList: currData,

            replypageNum: pageNum + 1,

            replysearchLoading: false

          })

        }

        if (jsonObj.statusCode == 205) {

          _this.setData({

            replysearchLoading: false

          })

        }

      }

    })

  },

把数组变成对象？你用的啥方法啊