The invention discloses a capacity configuration method used for a grid-connected wind and light storage system. The method includes following steps: selecting a target area; acquiring the wind speed, the solar irradiation intensity, the ambient temperature, and the electricity consumption power of a typical year of the target area; determining the maximum possible installation capacity of a wind generating set and a photovoltaic array of the target area according to the wind speed, the solar irradiation intensity, and the ambient temperature of the typical year of the target area; obtaining the complementary characteristics of wind energy and luminous energy of the target area according to the wind speed, the solar irradiation intensity, and the ambient temperature of the typical year of the target area; calculating and obtaining the configuration capacities of the wind generating set and the photovoltaic array according to the complementary characteristics of the wind energy and the luminous energy of the target area; and calculating and obtaining configuration parameters of an energy storage battery according to the configuration capacities of the wind generating set and the photovoltaic array of the target area. According to the capacity configuration method, the configuration capacities of the wind generating set and the photovoltaic array can be used to the maximum, and the generating utilization rate of the wind generating set and the photovoltaic array can be increased.