The present invention discloses a wind power generation system peak regulation capacity assessment method. The method comprises: obtaining load prediction, unit combination information and numerical weather prediction information; employing a wind power output reliability model to calculate a wind power negative fluctuation risk and a wind field income to obtain a peak regulation capacity prediction value; and determining whether the system correction control is performed or not. The method provided by the invention employs an optimal load reduction model according to an element integration shutdown model and a wind power plant reliability model, when generation is unbalance and a line power flow is out of limit, the method can automatically simulate the correction control strategy of the system and optimize generating capacity and load shedding capacity to switch a line, and the method considers a unit gradeability constraint, generation balance constraint and transmission network constraint, and employs an MC method to perform state sampling, performs quantization the contribution degree of the wind power plant output fluctuation for the risk and the income in the operation scale through the wind power fluctuation risk index and the wind power plant income index and describes the influences of the wind power plant on the system scheduling operation from the aspects of risk and economy.