Since road electric vehicles typically require a significantly variable and random load power demand in response to traffic conditions, such as frequent sequences of acceleration and deceleration and uphill followed by downhill runs. In this context, the energy management system of electric vehicle must ensure an effective power distribution between battery and supercapacitor to satisfy load demand. In this paper, the power management control strategy of hybrid energy storage system is developed by introducing terrain information to optimize system efficiency and battery lifetime. In this presented research, we aim at developing a power management control strategy considering the influence of the terrain information on system efficiency and battery lifetime. In order to avoid rapid changes of power demand and achieve high efficiency without degrading the mechanism performance, a Haar wavelet transform algorithm is proposed to decompose different frequencies components of the load power demand. In addition, the dynamic relationships are also established between the desired supercapacitor voltage and vehicle velocity and terrain to guide the power distribution. Finally, the hybrid system models are developed using MATLAB/Simulink simulation software and validated using experiment data. Simulation results have shown that the proposed control strategy is valid and effective in improving system efficiency and battery lifetime.