With the burst-up of transportation demand, the scale of urban rail transit expands, and the complexity of transit network enhances. Modern communication technology renders methods to collect passenger flow data with ease and accuracy. From traffic OD and travel time, there is no intuitive and quantitative method to collect and grasp the travel path and distribution of passenger flow. Modeling the rail transit network, establishing a quantitative impedance model from time, money and other comprehensive factors, simulating the travel path selection behavior of passengers in a quantitative way, and then transforming OD data into the distribution of passenger flow in the network, can understand the passenger flow operation rules, and also can better classify ticket business, which provides reference for business analysis of various operation investors, and has practical significance. Based on the current situation of Suzhou rail transit and OD passenger flow data, this paper establishes the rail transit network topology model, comprehensively establishes the passenger travel cost model from multiple perspectives, searches for paths, improves the effective path set in combination with the actual situation, and obtains the passenger flow distribution results of the simulated line network through multiple iterations, which helps simulation on the real-time passenger flow status.