The winter camp invited the winners of senior high school mathematics leagues in all provinces, autonomous regions and municipalities directly under the Central Government and the teams from Hong Kong, Macao, Russia and Singapore to participate, with about 200 people (now it has been expanded to about 300 people). The distribution principle is that there are at least three people in each province and city, and then the scores are set to be preferred. The winter camp lasts five days. The first day is the opening ceremony, the second and third days are the exams, the fourth day is the academic report or sightseeing, and the fifth day is the closing ceremony to announce the exam results and awards.

The CMO exam is completely simulated by IMO, with 3 questions a day and 4.5 hours in a limited time. Each question is 21(three times as many as IMO questions, in order to conform to the cognitive habits of China people), and the full score of six questions is 126. The topic is more difficult than the International Mathematical Olympics, and it is highly technical. Awards are similar to IMO, first prize, second prize and third prize. The top 30 players with the highest scores will form the China National Training Team to participate in the International Mathematical Olympiad (IMO). Winners can be admitted to Peking University, Tsinghua University, Fudan University, Nanjing University, China University of Science and Technology, Zhejiang University and Shanghai Jiaotong University.

Since 1990, the team competition of Chen Shengshen Cup has been held in the winter camp. Starting from 199 1, the national middle school students' mathematics winter camp was officially named China Mathematical Olympics (CMO), which became the highest level, largest scale and most influential middle school students' mathematics competition in China.