This study divides the passenger travel path and constructs a mixed integer programming model for solving the cross-line operation plan of urban rail transit train. The optimization goal of model is to minimize the sum of passenger travel cost and enterprise operating cost. The model takes into account the constraints of passenger flow demand, train driving conditions and passenger service level, and is solved by using the enumeration method in short computation times. Through the analysis on the local urban rail transit network in a city, the model results are evaluated by the number of cross-line passenger flow, proportion of cross-line passenger flow, average transfer time of passengers, through rate for cross-line passengers and transfer coefficient. The results show that the operation of cross-line trains among different lines can effectively reduce the number of transfer and the travel time for cross-line passengers, and reduce the operating costs of enterprises.