Abstract: Due to the advantages of both capacity and power devices, hybrid energy storage technology is suitable for the recovery and utilization of metro braking energy. In this paper, the hybrid energy storage system (HESS) based on ground mode and dual DC/DC architecture is introduced. With a study on the parameter design methods of the bidirectional DC/DC converter, battery and super-capacitor packs, a simulation model is built by MATLAB, and compared with the single energy storage system in terms of control effect and system economy. The results show that the designed HESS makes the traction grid voltage in safe range during the whole braking process. Because of the small investment cost and volume quality, the prominent cost-effective advantage, HESS can effectively realize the function of standby power supply under emergency conditions. Hence the rationality of HESS and its parameter design are verified.