IOS不自动弹出键盘，必须手动触发一下focus才行，不能自动调用，所以需要诱导用户点击某个按钮触发focus，最终修改的方法，默认隐藏密码输入框，隐藏不能用v-if或者是v-show,用position:absolute, top:-1000,然后点击输入密码将top改为视窗内，并且调用focus的方法

代码如下，有问题欢迎评论

<template>
  <div class="pwdpush-box">
    <h4 class="enter-password" @click="enterPwd">输入密码</h4>
    <div class="phonenum-show"  :class="pushShow?'':'write-phonenum-1000'">
      <div class="write-phonenum">
        <p @click.prevent="pushShow = false">使用余额支付 8864</p>
        <p>支付密码：</p>
        <ul class="write-input clearfix">
          <input type="tel"  ref="input" maxlength="6" class="realInput" v-model="realInput" autofocus @keyup="getNum()"  v-focus @keydown="delNum()">
          <li v-for="disInput in disInputs"><input type="tel" maxlength="1" disabled  v-model="disInput.value"></li>
        </ul>
        <mt-button size="large" style="margin-top:80px;" @click="goPay">确认支付</mt-button>
      </div>
    </div>
  </div>
</template>

<script>
import { Field,Toast ,Indicator} from 'mint-ui';
import {headerNav,bottomShow} from '../../vuex/actions/actionDoc'
export default {
  name: 'packe',
  vuex: {
    actions:{
      headerNav,
      bottomShow
    }
  },
  data(){
    return{
      messagepacket:false,
      packets:[

      ],
      disInputs:[{value:''},{value:''},{value:''},{value:''},{value:''},{value:''}],
      realInput:'',
      pushShow:false

    }
  },
  mounted(){
    this.headerNav(false)
    this.bottomShow(false)
  },
  methods:{
    getNum(){
      for(var i=0;i<this.realInput.length;i++){
        this.disInputs[i].value=this.realInput.charAt(i)
        // 表示字符串中某个位置的数字，即字符在字符串中的下标。
      }
    },
    delNum(){
      var oEvent = window.event;
      if (oEvent.keyCode == 8) {
        if(this.realInput.length>0){
          this.disInputs[this.realInput.length-1].value=''
        }
      }
    },
    goPay(){
        console.log(this.realInput)
    },
    enterPwd(){
        this.pushShow = true;
        this.$refs.input.focus()
    }
  }
}
</script>
<style lang="less" sconed>
  .enter-password{
    text-align: right;
    color:#1D890D;
    font-size: 18px;
    line-height: 2;
    margin-top:20px;
    padding-right: 20px;
  }
  .phonenum-show{
    background: rgba(0,0,0,0.6);
    position: absolute;
    top:0;
    right:0;
    bottom:0;
    left:0;
    z-index: -1;
  }
  .getback-title span{position: absolute;right:0;top:3px;width:15px;height:15px;display: inline-block;}
  .write-phonenum-1000{
    top:-1000px!important;
  }
  .write-phonenum{
    position: absolute;
    top:50%;
    margin-top:-100px;
    left:0;
    right:0;
    bottom:0;
    z-index: 2;
    padding:30px 10px 0;
    background: #fff;
  }
  .write-phonenum p{
    font-size: 14px;
    margin-left:30px;
    line-height:2;
  }
  .write-phonenum p span{color: #3b90d1;}
  .write-input {width:312px; margin:10px auto; position: relative;}
  .write-input li{float: left;width:30px;height:30px; margin: 0 10px; border:1px solid #888888;}
  .write-input li input{-webkit-appearance: none;-moz-appearance: none;-ms-appearance: none;resize: none;outline: none;border:0;width:30px;line-height: 30px;text-align: center;height: 30px;font-size:16px;}
  .write-phonenum .mint-button--default{background: #3b90d1;color:#fff;font-family: "微软雅黑";font-size: 14px;width:80%;margin:10px auto;}
  .realInput{
    /* Keyword values */
    -webkit-appearance: none;
    -moz-appearance: none;
    -ms-appearance: none;
    resize: none;
    outline: none;
    border: 0;
    z-index: 3;
    position: absolute;
    width: 290px;
    height: 30px;
    line-height: 30px;
    background: none;
    display: block;
    left: 50%;
    margin-left: -145px;
    top: 34px;
    opacity: 0;
    font-size: 0px;
    caret-color: #fff;
    color: #000;
    text-indent: -5em;
    font-size: 30px;
    top:1px;
  }
  input[type="tel"]:disabled{background-color: #fff;}
</style>