看起来是因为 chrome 正在寻找 favicon.ico(导致 404)，而我的 .htaccess 文件将所有 404 指向 index.php 文件，该文件再次执行代码.

It looks like it was because chrome was looking for favicon.ico (which caused a 404) and my .htaccess file points all 404s to index.php file which executed the code again.