A series hydraulic hybrid power system was designed for the vehicles frequent start and stop. Based on the system, an energy management strategy for the vehicle with the system was proposed in which a pressure of accumulator was set for engine power supply.The simulation model of the series hydraulic hybrid power system was constructed by using AMESim, and the energy saving influenced by gas precharge pressure of accumulator and other parameter were discussed. The simulation results show that the system can recover and reuse energy during the vehicle barking and driving, ensure the engine working when the accumulator energy is given out, and reduce vehicle energy consumption.