The research group of supercapacitor energy storage system in urban rail way is the group that conducted research on regenerative braking energy recovery with supercapacitor at very early time in China. During train’s traction, the stored energy in supercapacitor will release back to the train, achieving the purpose of regenerative energy utilization. In previous stage, the group made theoretical analysis on the train-traction power network model and proposed intelligent control strategies of supercapacitor-based energy storage system. They collaborated with Beijing Mass Transit Railway Operation Corporation Limited, conduct filed tests on Beijing Metro Batong Line and verified the proposed control strategies. Results showed that the energy saving rate was more than 10%. After research on the bottom -layer model and middle-layer control, the group now focuses on the up-layer of systematic design. They consider the system with multiple trains, make cooperative control of energy storage systems and multiple trains, and adjust the train diagram, realizing the improvement of energy saving effect of the entire power supply system. With the increasingly widespread use of supercapacitors, their lifetime has caused a great deal of concern. To accurately diagnose a state of health (SOH) of the supercapacitor, Our team tests the characteristics of supercapacitor cells to establishes more accurate equivalent circuit models, temperature rise models, and to predict their lifetime. The energy management strategy of energy storage system is optimized in the whole life cycle.