In view of the problems of short battery life and driving distance of electric vehicles, super-capacitors, batteries and DC/DC converters are introduced to form vehicle-mounted hybrid energy storage systems. Based on the circuit average model of the five-order state space, a global sliding mode control strategy based on exponential reaching law(E-GSM) is proposed, and the stability of the control strategy is analyzed based on the Lyapunov method. The strategy includes a global sliding mode current controller which can accurately track the current reference value of the battery and super-capacitor, and a PI controller which can stabilize the bus voltage. At the same time, an improved rule-based energy management strategy is proposed to generate the current reference value of the battery. The simulation results show that the E-GSM control strategy can accurately track the change of load power. Under typical urban conditions in China and new Europe driving conditions, the final SOC value of the battery has increased by 10% and 7%, respectively, and the high current discharge of the battery can be avoided, which can verify the effectiveness of the E-GSM control strategy.