import img from './../../../../asset/img/user.png'

<img src={require('../images/picture.png')} alt="标签"/>

.img {
   background: url('../images/picture.png') 0 0 no-repeat;
}

// 引入图片文件
import bg from '../images/bg.png'
// 通过字符串拼接的方式定义一个样式对象
const imgStyle = {
  width: '100%',
  height: '500px',
  backgroundImage: 'url(' + bg + ')',
  backgroundPosition: 'center 0',
  backgroundSize: '2045px 472px',
  backgroundRepeat: 'no-repeat'
}
class Home extends Component {
 constructor () {
  super (props)
 }
 render() {
  // 最后直接将变量赋值给标签
  <div style="imgStyle">
   ...
  </div>
 }
}

<img width="100" height="100" src={require('./../../../../asset/img/user.png').default} alt="" className={'user-img'}/>