.rui-justify{text-align: justify;}
.rui-justify::after{
content: '';
display: inline-block;
padding-left: 100%;
}
<view class='rui-form-li'>
<view class='rui-form-li-name rui-justify'>姓名</view>
<view class='rui-form-li-input'><input name="name" placeholder='请填写您的真实姓名' value=''></input></view>
</view>