安装

​​npm i mini-css-extract-plugin --save-dev​​

修改 ​​webpack.config.js​​

const MiniCssExtractPlugin = require('mini-css-extract-plugin');
 
module.exports = {
    module: {
        rules: [
            {
                test: /\.css$/,
                use: [
                    'style-loader',
                    MiniCssExtractPlugin.loader, 
                    'css-loader'
                ]
            }
        ]
    },
    plugins: [
        new MiniCssExtractPlugin({
            filename: 'css/main.css'
        })
    ]
};