The invention provides a wind-electricity-participated electric power system frequency modulation method and system. The wind-electricity-participated electric power system frequency modulation method includes the steps: S1, according to the practical wind speed operated by a wind turbine generator set, determining the operating area of the wind turbine generator set; S2, according to the practical frequency of the electric power system, determining the frequency offset of the electric power system; and S3, according to the operating area of the wind turbine generator set, based on the frequency offset of the electric power system, utilizing the wind turbine generator set to modulate the frequency of the electric power system. According to the operating area of the wind turbine generator set, the wind-electricity-participated electric power system frequency modulation method and system can utilize the wind turbine generator set to modulate the frequency of the electric power system, thus being able to fully exert the self frequency modulation capability of the wind turbine generator set and maintain stable frequency of the electric power system on the premise of not influencing the operating benefit of the wind turbine generator set.