Abstract: Aiming at the service life of hybrid energy storage units in independent DC microgrids,the control strategy of hybrid energy storage units based on voltage droop control is proposed,and the improvement measures of the control strategy of hybrid energy storage system are proposed. Firstly,steady-state power correction strategy based on supercapacitor state of charge is used to restore the charge state of supercapacitor to the initial rating after a period of operation,so as to avoid overcharge or over-discharge of supercapacitor.Secondly,in view of battery service life,an energy management strategy based on the charged state of mixed energy storage is proposed to achieve the purpose of prolonging the battery service life. Finally,through Matlab/Simulink simulation analysis,it is proved that the proposed method can effectively extend the service life of batteries and supercapacitors under the condition of changing the photovoltaic output power.