在库的angular.json文件的styles数组中添加字体文件路径，同时将导入字体文件的URL改为相对路径。

示例代码：

"styles": [
  "src/styles.scss",
  "node_modules/font-awesome/css/font-awesome.css",
  "src/assets/fonts/font-awesome-webfont.woff2"
],

将CSS中的字体导入路径改为相对路径：

@font-face {
  font-family: 'FontAwesome';
  src: url('../../assets/fonts/font-awesome-webfont.eot?v=4.7.0');
  src: url('../../assets/fonts/font-awesome-webfont.eot?#iefix&v=4.7.0') format('embedded-opentype'),
       url('../../assets/fonts/font-awesome-webfont.woff2?v=4.7.0') format('woff2'),
       url('../../assets/fonts/font-awesome-webfont.woff?v=4.7.0') format('woff'),
       url('../../assets/fonts/font-awesome-webfont.ttf?v=4.7.0') format('truetype'),
       url('../../assets/fonts/font-awesome-webfont.svg?v=4.7.0#fontawesomeregular') format('svg');
  font-weight: normal;
  font-style: normal;
}