需求：默认有一组输入框，可动态添加，支持删除！（ui基于vant-weapp)

wxml

<view class="cash_container">
  <view class="input_groups bg_page pa_10">
    <view class="input_item bg_white mb_10" wx:for="{{inputList}}" wx:for-item="inputItem" wx:key="index">
      <van-field label="面值(元)" value="{{inputItem.parValue}}" type="digit" data-index="{{index}}" bind:change="onParValueChange"
        placeholder="请输入" required clearable />
      <van-field label="数量(张)" value="{{inputItem.num}}" type="digit" data-index="{{index}}" bind:change="onNumChange"
        placeholder="请输入" border="{{false}}" required clearable />
      <view class="del_wrap" data-index="{{index}}" bindtap="onDelete" wx:if="{{index !== 0}}">
        <van-icon name="delete" color="#FF3F35" />
      </view>
    </view>
    <van-button icon="plus" type="info" bind:click="onAdd">添加面值</van-button>
  </view>

  <view class="btn_wrapper tc pa_20">
    <button class="btn_gradient" bindtap="onSubmit">提 交</button>
  </view>
  <van-notify id="van-notify" />
</view>

js

import Notify from '../../../miniprogram_npm/@vant/weapp/notify/notify';
Page({

  /**
   * 页面的初始数据
   */
  data: {
    listId: '',
    inputList: [{
      parValue: '',
      num: ''
    }]
  },

  onParValueChange: function (e) {
    let val = e.detail,
      i = e.currentTarget.dataset.index,
      item = this.data.inputList[i];
    item['parValue'] = val;
    console.log(item);
  },
  onNumChange: function (e) {
    let val = e.detail,
      i = e.currentTarget.dataset.index,
      item = this.data.inputList[i];
    item['num'] = val;
    console.log(item);
  },
  // 添加面值
  onAdd: function () {
    let obj = {
        parValue: '',
        num: ''
      },
      list = this.data.inputList;
    list.push(obj);
    this.setData({
      inputList: list
    });
    console.log(this.data);
  },
  // 删除面值
  onDelete: function (e) {
    let i = e.currentTarget.dataset.index,
      list = this.data.inputList;
    console.log(i);
    list.splice(i, 1);
    this.setData({
      inputList: list
    });
  },
  // 提交
  onSubmit: function (e) {
    console.log(this.data)
  },
  /**
   * 生命周期函数--监听页面加载
   */
  onLoad: function (options) {
    if (options) {
      this.setData({
        listId: options.listId
      });
      wx.setNavigationBarTitle({
        title: options.title
      })
    }
  },

  /**
   * 生命周期函数--监听页面初次渲染完成
   */
  onReady: function () {

  },

  /**
   * 生命周期函数--监听页面显示
   */
  onShow: function () {

  },

  /**
   * 生命周期函数--监听页面隐藏
   */
  onHide: function () {

  },

  /**
   * 生命周期函数--监听页面卸载
   */
  onUnload: function () {

  },

  /**
   * 页面相关事件处理函数--监听用户下拉动作
   */
  onPullDownRefresh: function () {

  },

  /**
   * 页面上拉触底事件的处理函数
   */
  onReachBottom: function () {

  },

  /**
   * 用户点击右上角分享
   */
  onShareAppMessage: function () {

  }
})

wxss

.input_item {
  position: relative;
  padding: 10rpx;
  border-radius: 5px;
}

.input_item .del_wrap {
  position: absolute;
  top: 0;
  right: 0;
  padding: 10rpx;
}

引入vant-weapp 组件的json

{
  "usingComponents": {
    "van-row": "@vant/weapp/row/index",
    "van-col": "@vant/weapp/col/index",
    "van-field": "@vant/weapp/field/index",
    "van-notify": "@vant/weapp/notify/index",
    "van-icon": "@vant/weapp/icon/index",
    "van-button": "@vant/weapp/button/index"
  }
}