5 10275。 According to the query of the Undergraduate Admissions Network of Sun Yat-sen University, the postal code of the Admissions Office of the Academic Affairs Office is 5 10275. Sun yat-senu university (CUHK for short) is a modern comprehensive university located in Guangdong Province, China, which is affiliated to the Ministry of Education of People's Republic of China (PRC) and jointly built by the Ministry of Education and the People's Government of Guangdong Province.