Abstract: Battery energy storage system（BESS） can be used to smooth out the fluctuations of the scenery, but because of the single evaluation index for their selection, it is difficult to coordinate the technical, economic and environmental aspects of different types of energy storage systems in their selection planning and charging/discharging power allocation. In this paper, a comprehensive evaluation system for BESS considering the synergy of "wind-photovoltaic-battery" is proposed, then the charging and discharging strategies for BESS are optimized and selected. Firstly, the benefits of the BESS are modeled over its whole life cycle, and fuzzy analytic hierarchy process（FAHP） is used to analyze the above benefits model of BESS in a hierarchical manner, dividing it into different criteria and indicators, and deriving their corresponding weights; Secondly, the charge/discharge power optimization model of the BESS under the synergy of "wind-photovoltaic-battery" is established, which is combined with the above weights, including the economic, technical and environmental aspects of the BESS during its whole life cycle then, the objective function is determine; Thirdly, in this paper,a hybrid optimization algorithm combining Grey Wolf algorithm and Lévy flight strategy（LF-GWO） is proposed, which determines to optimize the distribution of charging and discharging power of BESS for each hour in a day, and derives the SOC of BESS; Finally, the example is used to analyze and compare the economic, environmental and technical indexes of five types of BESS based on the meteorological and load data of a place in Xinjiang, and the result of example makes suggestions for the selection scheme and charging/discharging power allocation of the BESS, which also verifies the feasibility of the proposed model and the superiority of the solution algorithm.