Due to intermittency, uncertainty and real-time change of load of power output of distributed micro grid, hybrid energy storage device should be used to meet the needs of power balance. This paper proposes a hybrid energy storage system composed of several battery and super capacitor to meet the needs of both power and energy at the same time. And a power allocation method based on the SOC parameter was put forward by combining the droop control method with the SOC parameter of different hybrid energy storage subsystem. The above strategy verified by experiments show that it can allocate storage battery and super capacitor output value, effectively reduce the battery charge and discharge times, prolong its service life.