//密码为八位及以上并且字母数字特殊字符三项都包括
    var strongRegex = new RegExp("^(", "g");
    //密码为七位及以上并且字母、数字、特殊字符三项中有两项，强度是中等
    var mediumRegex = new RegExp("^(", "g");
    var enoughRegex = new RegExp("(", "g");

 <div class="wrapper">
  <div class="input_box">
  <input type="password" name="" placeholder="请输入密码" oninput="passValidate(this)" id="inputPwd" value="">
  <div class="eye_icon"></div>
  </div>
  <p>请至少使用字母、数字、符号两种类型组合的密码，长度为6~20位。</p>
  <ul class="pwdStrength">
   <li class="weak"></li>
   <li class="middle"></li>
   <li class="strong"></li>
   <li class="result"></li>
  </ul>
</div>

 * {
   margin: 0;
   padding: 0;
   box-sizing: border-box;
  }

  .wrapper {
   width: 500px;
   height: 200px;
   border: 1px solid #eee;
   margin: 100px auto;
   display: flex;
   align-items: center;
   flex-direction: column;
  }
  .input_box{
   width: 80%;
   display: flex;
   align-items: center;
  }
  .input_box input {
   width: 82%;
   height: 30px;
   border: none;
   outline: none;
   border: 1px solid #D2B48C;
   border-radius: 12px;
   margin: 10px 0px;
   padding-left: 15px;
  }
  .eye_icon{
   width: 20px;
   height: 20px;
   background-image: url('./open_eye.png');
   background-repeat: no-repeat;
   background-position: center content;
   background-size: cover;
   margin-left: 10px;
  }
  .wrapper p {
   width: 80%;
   height: 60px;
   line-height: 26px;
   font-size: 14px;
   color: #339999;
  }

  .pwdStrength {
   width: 80%;
   list-style: none;
   height: 30px;
   display: none;
   flex: 1;
  }

  .weak,
  .middle,
  .strong {
   height: 15px;
   width: 30px;
   border: 1px solid black;
   background: rgb(238, 238, 238);

  }

  .middle {
   border-left: 0;
   border-right: 0;
  }

  .result {
   width: 30px;
   height: 15px;
   font-size: 14px;
   line-height: 14px;
   text-align: center;
   margin-left: 10px;
  }

//密码的可见与隐藏、
  console.log($('#inputPwd'))
  var eyeFlag = false;
  $('.eye_icon').click(function(){
   if(!eyeFlag){
    $(this).css({'background-image': 'url(' + "./close_eye.png" + ')'});
    $('#inputPwd').attr('type','text');
   }else{
    $(this).css({'background-image': 'url(' + "./open_eye.png" + ')'});
    $('#inputPwd').attr('type','password')
   }
   eyeFlag = !eyeFlag;
  })
  //密码强度验证
  function passValidate(e) {
   var pwd = $.trim(e.value);
   if (pwd === '') {
    $('.pwdStrength').css({'display':'none'})
    $('.weak').css({
     'background': 'rgb(238, 238, 238)'
    });
    $('.middle').css({
     'background': 'rgb(238, 238, 238)'
    });
    $('.strong').css({
     'background': 'rgb(238, 238, 238)'
    });
    $('.result').text('')
   } else {
    $('.pwdStrength').css({'display':'flex'})
    //密码为八位及以上并且字母数字特殊字符三项都包括
    var strongRegex = new RegExp("^(", "g");
    //密码为七位及以上并且字母、数字、特殊字符三项中有两项，强度是中等
    var mediumRegex = new RegExp("^(", "g");
    var enoughRegex = new RegExp("(", "g");
    if (false == enoughRegex.test(pwd)) {
    } else if (strongRegex.test(pwd)) {
     $('.strong').css({
      'background': '#33ff33'
     });
     $('.result').text('强')
    } else if (mediumRegex.test(pwd)) {

     $('.middle').css({
      'background': '#FFC125'
     });
     $('.strong').css({
      'background': 'rgb(238, 238, 238)'
     });
     $('.result').text('中')
    } else {

     $('.weak').css({
      'background': '#EE4000'
     });
     $('.middle').css({
      'background': 'rgb(238, 238, 238)'
     });
     $('.strong').css({
      'background': 'rgb(238, 238, 238)'
     });
     $('.result').text('弱')
    }
   }
}