<input id="tmsfzhm" οninput="hiddens2()" pattern="\d*" type="text" placeholder="请输入身份证号码">

<input id="sfzhm"  type="hidden" placeholder="请输入身份证号码">

<script>

var jiamiValue = "";

  var zhenshiValue = "";
  function hiddens(){
  jiamiValue = document.getElementById('tuominhaoma').value;
  zhenshiValue = document.getElementById('zhengjianhaoma').value;
  //判断为增加还是删除
  var value = document.getElementById('tuominhaoma').value;
  if (value.length < zhenshiValue.length) {//删除
  var changeLength = zhenshiValue.length-value.length;
  zhenshiValue = zhenshiValue.substring(0,zhenshiValue.length-changeLength);
  jiamiValue=value;
  document.getElementById('tuominhaoma').value = jiamiValue;
  } else if (value.length > zhenshiValue.length){//增加
  zhenshiValue = zhenshiValue+value.substring(value.length-1,value.length);
  if(zhenshiValue.length>1&&zhenshiValue.length<18){
  jiamiValue = value.substring(0,value.length-1)+"*";
  }else{
  jiamiValue=value;
  }
   document.getElementById('tuominhaoma').value = jiamiValue;
  }
 document.getElementById('zhengjianhaoma').value = zhenshiValue;
 

  }

</script>