SOURCE

$(".ipt-real-nick").on("input", function() {
	//console.log($(this).val());
	var $input = $(".ipt-fake-box input");
	if(!$(this).val()){//无值光标顶置
		$('.ipt-active-nick').css('left',$input.eq(0).offset().left-parseInt($('.ipt-box-nick').parent().css('padding-left'))+'px');
	}
	if(/^[0-9]*$/g.test($(this).val())){//有值只能是数字
		//console.log($(this).val());
		var pwd = $(this).val().trim();
		for (var i = 0, len = pwd.length; i < len; i++) {
			$input.eq(i).val(pwd[i]);
			if($input.eq(i).next().length){//模拟光标，先将图片容器定位，控制left值而已
				$('.ipt-active-nick').css('left',$input.eq(i+1).offset().left-parseInt($('.ipt-box-nick').parent().css('padding-left'))+'px');
			}
		}
		$input.each(function() {//将有值的当前input后的所有input清空
			var index = $(this).index();
			if (index >= len) {
				$(this).val("");
			}
		});
		if (len == 6) {
			//执行其他操作
			console.log('输入完整，执行操作');
		}
	}else{//清除val中的非数字，返回纯number的value
		var arr=$(this).val().match(/\d/g);
		$(this).val($(this).val().slice(0,$(this).val().lastIndexOf(arr[arr.length-1])+1));
		//console.log($(this).val());
	}
});

<div>
    <div class="lh40-nick h40-nick fwb-nick">请在下方输入6位数字</div>
    <div class="ipt-box-nick mb15-nick">
        <input type="tel" maxlength="6" class="ipt-real-nick"/>
        <div class="ipts-box-nick">
            <div class="ipt-fake-box">
                <input type="text" >
                <input type="text" >
                <input type="text" >
                <input type="text" >
                <input type="text" >
                <input type="text" >
            </div>
        </div>
        <div class="ipt-active-nick"><img src="https://t.alipayobjects.com/images/rmsweb/T1nYJhXalXXXXXXXXX.gif"></div>
    </div>
</div>
<script src="//cdn.bootcss.com/jquery/3.1.1/jquery.min.js"></script>

.ipt-box-nick {
	width:300px;
	height: 40px !important;
	line-height: 40px !important;
	position: relative !important; }
.ipt-box-nick .ipt-real-nick {
	position: absolute !important;
	top: 0 !important;
	left: 0 !important;
	width: 100%;
	height: 40px !important;
	line-height: 40px !important;
	opacity: 0 !important;
	z-index: 3 !important; }
.ipt-box-nick .ipts-box-nick {
	position: absolute !important;
	top: 0 !important;
	left: 0 !important;
	z-index: 1 !important;
	width: 100%;
	height: 40px !important;
	line-height: 40px !important;
	overflow: hidden; }
.ipt-box-nick .ipts-box-nick .ipt-fake-box {
	height: 40px !important;
	line-height: 40px !important;
	display: flex !important;
	justify-content: space-between !important; }
.ipt-box-nick .ipts-box-nick .ipt-fake-box input {
	width: 40px !important;
	height: 38px !important;
	border: 1px solid #D7D7D7 !important;
	color: #810213 !important;
	font-weight: bold !important;
	font-size: 18px !important;
	text-align: center !important;
	padding: 0 !important;
	border-radius:2px;}
.ipt-box-nick .ipt-active-nick {
	width: 40px !important;
	height: 40px !important;
	line-height: 40px !important;
	text-align: center;
	position: absolute !important;
	top: 0;
	left: 0;
	z-index: 2; }
.ipt-box-nick .ipt-active-nick img {
	vertical-align: middle; }