<form>
    <div>
        <input id="item1" type="radio" name="item" value="选项一" checked>
        <label for="item1"></label>
        <span>选项一</span>
    </div>
    <div>
        <input id="item2" type="radio" name="item" value="选项二">
        <label for="item2"></label>
        <span>选项二</span>
    </div>
</form>

div {
            position: relative;
            line-height: 30px;
        }
        
        input[type="radio"] {
            width: 20px;
            height: 20px;
            opacity: 0;
        }
        
        label {
            position: absolute;
            left: 5px;
            top: 3px;
            width: 20px;
            height: 20px;
            border-radius: 50%;
            border: 1px solid #999;
        }
        
        /*设置选中的input的样式*/
        /* + 是兄弟选择器,获取选中后的label元素*/
        input:checked+label { 
            background-color: #fe6d32;
            border: 1px solid #fe6d32;
        }
        
        input:checked+label::after {
            position: absolute;
            content: "";
            width: 5px;
            height: 10px;
            top: 3px;
            left: 6px;
            border: 2px solid #fff;
            border-top: none;
            border-left: none;
            transform: rotate(45deg)
        }

　　源码链接：http://runjs.cn/code/hmevb9gs