Abstract: This paper conducted a study on passenger flow assignment based on the travel preferences of different groups of travelers (referred to as "groups"), considered the differences in sensitivity of each group to various aspects of the travel process, and defined the subjective travel costs of each group. The paper constructed a three-dimensional travel network of "time - space -group" to describe the different travel behaviors of each group of passengers during their travel process, and designed the travel network costs, constructed a network flow model based on train occupancy constraints, described the travel choices and capacity occupancy processes of various groups, and solved the passenger flow distribution status of travel routes for various groups at different levels. The analysis of passenger flow distribution on the Jing - Hu section (Beijing North - Hohhot East) of the Beijing - Lanzhou high-speed railway shows that different groups' travel preferences have a significant impact on passenger flow distribution and transfer. This passenger flow assignment method can not only well describe the sensitivity of different travel groups to different travel plans, depict the competitive game process of passengers among different groups for limited transportation resources, but also evaluate transportation capacity allocation, which has reference significance for railway passenger transport capacity adjustment and passenger transport product design.