Abstract: Optimizing the running state of tram is a simple, reliable and effective method to reduce the energy consumption of tram. However, there is still a lack of relevant research on tram passing through intersection smoothly without stopping, while considering the influence of traffic lights on the running state of tram between stations and by optimizing the speed trajectory of tram. Taking energy-storage tram as research object, the scene based environment model and train kinematics model are established. Taking the total energy consumption of tram in the running process as the optimization objective, model constraints are established according to the tram exit/entry states and the timing information of traffic lights. Radau pseudo-spectral method is adopted to optimize the speed trajectory of tram to achieve the minimum total energy consumption in the running process. Simulation results show that the algorithm enables the tram to pass through the signalized intersection smoothly, rapid acceleration and deceleration caused by reaching the stop line at the red-light time window are avoided, and the total energy consumption is reduced by 23.45%.