Abstract: Through the high matching of transport capacity supply and passenger flow demand, the flexible marshalling mode can provide a new solution to improve the service quality of urban rail operation. Firstly, the limiting factors were systematically analyzed. And then, from the perspective of improving the passenger waiting time equilibrium, in view of the problems of too long waiting time of passengers in the outer sections of the small crossing road under the operation mode, the optimization method of the marshalling number and the passenger waiting time calculation formula of the flexible marshalling scheme was proposed, and how to select the equilibrium optimization scheme from different flexible marshalling schemes was discussed. Finally, the example verification results show that that under the flexible organization of marshalling mode, the optimal scheme can improve the train full load rate, and reduce the passenger waiting time of 248.45 hours, and shorten the size of passenger average waiting time to 41%, and reduce the vehicle travel kilometers by 197.6 km, and effectively improve the equilibrium of passenger waiting time.