In recent years, new energy-storage vehicles in rail transit have developed rapidly. By adopting these vehicles, not only the construction difficulties, unsightly, and other problems of the traditional overhead contact line tram are solved, but energy savings and environmental protection during normal operation can also be improved thanks to the characteristics and advantages of in-vehicle energy storage components. Therefore, the energy storage power supply has gradually become the most potential power supply system for urban trams in China. Based on the above-mentioned, this chapter discusses the hybrid energy storage power system of tram which combines lithium batteries with high energy density and supercapacitors with high power density. Therefore, the hybrid energy storage system (HESS) allows for cost savings by complementing the advantages of the two components.