Taking photovoltaic - battery system as a research object, the sizing and operation optimization model of the photovoltaic-battery system based on decomposition-coordination method is constructed. Firstly, taking the comprehensive cost including the energy storage investment cost and the operating cost of the optical storage system as the objective function, the Benders decomposition method is used to decompose the model into the main problem of planning and configuration and the sub -problem of operation scheduling. Then the capacity investment cost of energy storage and system operation cost are divided as the objective function of the main problem and sub-problem, the optimal configuration plan of the energy storage battery and the optimal operation strategy of the system are obtained through decomposition, coordination and optimization. At the same time, set a series of indicators such as the photovoltaic consumption rate, self-sufficiency rate, internal rate of return, and dynamic investment recovery period to evaluate the model. In addition, the visualization of the accumulation process of Bender cut sets is realized, and visually the convergence process of the Benders decomposition method is showed. Based on this, the K- means cluster analysis algorithm is used to establish an annual pho tovoltaic output model, the optimal configuration of energy storage batteries on a long-term scale is solved, and the feasibility of solving the decomposition and coordination optimization model on the medium and long-term scale is explored.