International Mathematical Olympiad, referred to as IMO, is an international competition with mathematics as its content and middle school students as its object. It has a history of more than 30 years. As an international competition, the International Mathematical Olympiad was put forward by international mathematical education experts, which exceeded the level of compulsory education in various countries and was much more difficult than the college entrance examination. In 20 12 years, IMO has become the most influential academic competition in the world, and it is also recognized as the highest level mathematics competition for middle school students. The math contest in China started at 1956. At the initiative of famous mathematicians such as China and the Soviet Union, initiated by chinese mathematical society, the four cities of Beijing, Tianjin, Shanghai and Han took the lead in holding high school mathematics competitions.