The maximum aggregate number of high-speed rail terminal is the main basis for designing the termi- nal scale of the high-speed rail terminal. With the continuous development of high-speed railway, the travel pattern of passengers has undergone great changes and the passenger gathering rules of high-speed rail terminal are also changing. Based on the research results of the maximum aggregate number of existing railway terminals, this paper studied the calculation method of the maximum aggregate number of high-speed railway terminal, im- proved and modified the original probability calculation method. At the same time, by considering the effects of train frequency and the number of ticket-tipping on the aggregate number of high-speed rail terminal, it finds out that the distribution of waiting time for high-speed railway passengers conforms to the lognormal distribution. Then, it established the maximum aggregate number forecasting model of high-speed railway passenger terminal, and verified the above conclusion through case calculation.