之前使用type来控制，发现不行，修改为password属性即可

  <van-field
      right-icon="{{passwordType == 'password'? 'closed-eye':'eye-o'}}"
      model:value="{{ password }}"
      password="{{passwordType == 'password' ? true: false}}"
      border="{{ false }}"
      custom-class="password_style {{focusPassword ? 'blue':'none'}}"
      bind:click-icon="onClickIcon"
      focus="{{focusPassword}}"
    />