Through researching the power consumption strategy of microgrid, a bi-layer optimization model for microgrid is proposed in response to the situation that the power supply capacity of industrial parks cannot meet the demand for electricity loads. In the outer layer of the optimization model, an economic benefit model of photovoltaic-energy storage system is established, and the model uses payback period and internal rate of return as evaluation indicators of economic benefits. In the inner layer, the operating states of the microgrid, load, and energy storage system are taken as constraint conditions, and the cooperation between distributed photovoltaic, energy storage system and load is considered synchronously, and the model uses power supply reliability as an evaluation index to set up charging and discharging operation strategies of battery storage system. This paper selects an industrial park in the northwest region as the application scenario, and solves the optimization model to determine the optimal capacity configuration of the microgrid system. At the same time, by comparing and analyzing between the improved optimization scheme and the energy storage capacity configuration scheme that meets continuous power supply, it is found that the proposed energy storage capacity configuration can achieve optimal economic benefits, and its effectiveness and feasibility of the model are verified in practice.