Peking University is a well-known institution of higher learning in China, and its mathematics major enjoys a high reputation in the world. The enrollment of graduate students in the school has also attracted much attention, which may attract many outstanding fresh graduates and people from the society to apply for the exam. In some professional fields (such as big data), due to market demand, employment prospects and other factors, the proportion of related majors will be high or the degree of competition will be fierce.