Trump system, also known as "flexible curriculum", is a form of teaching organization proposed by American educator Ed Trump in 1950s. Trump system combines three teaching forms: large class, small class discussion and individual independent research. Large classes are taught collectively, and several parallel classes are taught uniformly, accounting for 40% of the class hours. 15 ~ 20 people form a small class to discuss the teaching content of the large class, accounting for 20% of the class hours. Finally, students study, research and finish their homework independently, accounting for 40% of the class hours.