Abstract: In order to study the influence of the accumulator energy storage status on vehicle working condition, the structure and the action principle of the series hydraulic hybrid vehicle is presented.The vehicle model was built in AMESim eviroment..On the basis of accumulator energy storage status, the pressure energy state was defined, and the rules of energy distribution was formulated, and whose controlling model was constructed in Simulink as the accumulator mathematical model.By means of the combination simulation between AMESim and Simulink, the accumulator energy storage status influence on working conditions of engine and regenerative braking for the typical conditions was analyzed.The simulation results show that the impact of energy storage setting pressure value of the accumulator is significant on the engine stop-start, a reasonable lower limit valve of pressure energy status should be set to 0.2;the accumulator had a larger range of upper and lower for pressure energy status during the engine start-stop repeatedly and slightly braking condition, which would be utilize to recover energy more effectively.