Theoretically speaking, civil servants are not allowed to work part-time, especially not allowed to use their power to work part-time in enterprises or units within their jurisdiction and earn income. It's not that strict. You can still work part-time if you have professional skills. For example, if you can design, you can do graphic design, interior design or draw pictures for people. Or you can play the piano and dance, and you can go to an art training school as a teacher in your spare time. Usually no one will pursue it.