If he wants to return to China with a master's degree in mathematics, it is relatively easy to find a job, because after all, his academic qualifications are still very high, and at the same time, he has foreign work experience and is more popular in China. If he wants to enter some industries with higher salaries, the most popular industries at present are the Internet industry or the mathematics R&D industry, which are very good choices. Of course, if he intends to engage in the teaching industry, he can also go to colleges and universities to engage in teaching, and he can be a doctoral or master tutor in the future.