With the regional economic integration and rapid development of metropolitan area,the operation environment of inter-city railway lines becomes more complex due to the mutual influence of various railway systems,which demands higher require-ments for the preparation of train operation diagram.From the perspective of intercity railway,this paper explores the competition and cooperation mechanism of multi-mode coupled transportation system.At the competitive level,the multinomial Logit model is used to evaluate the attractiveness of intercity railway to the passenger flow of this line;At the synergy level,the concept of connec-tion time window is introduced to analyze the transfer process between intercity railway and mainline railway under different connec-tion conditions.On this basis,considering the constraints of passenger flow,station and section capacity,occupancy rate,train opera-tion,etc.,a nonlinear integer programming model with the goal of maximizing the over passenger turnover and enterprise benefits is constructed,and a simulated annealing algorithm is designed to solve it.The results show that the multi-mode coupling optimization method of intercity railway train operation diagram can improve the share rate of intercity railway passenger transport to 39.57%,provide 81.97%of intermodal transfer service,and thus significantly enhance the service efficiency of intercity railway.