The invention relates to a double-layer optimizing operation method of an electric power system containing battery energy storage and a grid-connected wind power plant, and belongs to the technical field of power system operation optimization. The method of the invention includes: dividing wind storage joint operation into two stages of daily dispatching and real-time operation, and optimizing theplanned active power of thermal power and wind power plants by using the unit combination method considering the AC power flow constraint in the daily scheduling stage; and adopting an appropriate energy storage operation strategy to optimize wind storage joint operation in the real-time operation stage. The link between the two layers of optimization is achieved by parameter passing. The methodof the invention makes the operation strategy of energy storage of the wind power plant and the thermal power unit during daily planning and real-time operation more reasonable, thereby improving th acceptance capacity of a wind power plant of a power grid, reducing the grid operation cost and improving the precision of unit combination.