Abstract: To solve the issue of high life loss when the battery energy storage system（BESS）participates in photovoltaic power suppression,a power distribution method of BESS for photovoltaic power suppression considering state of health（SOH）and state of charge（SOC）is proposed. Firstly,the PV grid-connected standard,BESS capacity and maximum charge-discharge power are taken as the constraint conditions,and an optimization model of photovoltaic grid-connected signal is established with the objectives of gridconnected fluctuation rate,BESS life loss and SOC recovery. It is solved by the improved rain flow counting method optimized by improved aquila optimization algorithm. Then,a two-stage power allocation strategy of BESS is designed. Based on the traditional capacity dichotomy,exception group are introduced,and the capacity of the battery pack is dynamically adjusted. A BESS dynamic grouping method that takes into account both SOH and SOC is proposed,which is to realize the primary allocation of power instructions from BESS to the battery pack. Furthermore,the response ability of each battery cell is dynamically estimated by combining the standard deviation and range of SOH and SOC of the battery cell. The battery cell power distribution method based on SOH/SOC balance principle is designed to realize the secondary distribution of power command from battery pack to battery cell. Finally,the battery unit completes the adjustment in response to the power command. The typical daily output of a PV station equipped with BESS are used for simulation verification. Compared with other schemes,the results show that the proposed method reduces the SOH difference between battery groups,enhances the SOC consistency among battery units,and reduces the life loss of BESS with the satisfaction of the requirement of photovoltaic grid-connected fluctuation rate.