文档：
https://github.com/ritwickdey/vscode-live-sass-compiler/blob/master/docs/settings.md

配置文件 .vscode/settings.json

{
  "liveSassCompile.settings.generateMap": false,
  "liveSassCompile.settings.autoprefix": ["> 1%", "last 2 versions"],
  "liveSassCompile.settings.excludeList": ["**/node_modules/**", ".vscode/**"],
  "liveSassCompile.settings.formats": [
    {
      "format": "compressed",
      "extensionName": ".min.css",
      "savePath": "~/../css/"
    }
  ]
}

参考
live sass compiler-vscode插件将scss编译为css