The conventional simplified model of constant power cannot effectively verify the application effect of energy storage. In this paper, from the perspective of energy storage system level control, a general simulation model of battery energy storage suitable for integrated optical storage operation control is established. The model can reflect the external characteristics of large capacity energy storage system, and is a simplification of its internal multi-module complex chemical reactions. The data generated by the model in this paper is compared with the experimental data provided by the manufacturer. The results show that the model in this paper is more consistent with the physical and chemical characteristics of the actual battery energy storage power station, and provides a more effective simulation and verification tool for the planning and operation optimization control of the battery energy storage power station. Finally, the effect of battery energy storage on photovoltaic power output fluctuation is simulated and analyzed.