In order to evaluate the impact of airport peak on airport operation scientifically, and allocate airport operation support resources scientifically, traffic flow theory and system cluster analysis method are introduced to determine the peak period of airport operation. Studied the relationship between the peak flow of airport and the annual passengers, analyzed the distribution law of flight take-off and landing in the peak daytime. Taking the flight operation data of a large transport airport in China as an example, and then analyzed the data through the SPSS software, the feasibility of the method was verified, which provides a theoretical basis for determination of airport operation peak period scientifically.