The invention discloses a charging station optimization method considering echelon utilization of a power battery based on an MMC structure, and belongs to the field of planning optimization of an electric vehicle centralized charging station. According to the charging station optimization method of the invention, a decommissioned power battery is evaluated to lay a foundation for subsequent optimization research; secondly, an electric bus charging station structural design based on an MMC module is provided, and electric energy integrating new energy such as photovoltaic power generation, theelectric bus and the decommissioned power battery is collected; thirdly, the daily operation cost of the charging station is considered, and optimal configuration of energy storage of the photovoltaic, the electric buses and the decommissioned power batteries is performed on the established structural design based on the MMC module; finally, the feasibility and the effectiveness of the designed scheme and the optimization model are verified through examples.