<el-form-item>
          <span slot="label">
             <span class="formStar">[填]</span>
             <span class="formLabel">基本信息</span>
           </span>
        </el-form-item>

<style lang="scss" scoped>
.formStar {
  font-family: "PingFangSC-Semibold", "PingFang SC Semibold", "PingFang SC",
  sans-serif;
  font-weight: 200;
  font-style: normal;
  font-size: 12px;
  color: #fb0404;
  padding: 5px;
}
.formLabel {
  font-size: 20px;
  color: #333333;
  font-family: "MicrosoftYaHeiLight", "微软雅黑 Light", "微软雅黑", sans-serif;
  font-weight: 200;
  line-height: 30px;
}
</style>

formStar和formLabel是css样式按自己的意愿修改

<style lang="scss" scoped>  要加这个，不然就是全局修改