Abstract: With the increasing proportion of wind power and the large-scale application of primary frequency modulation technology, accurate calculation of the limit value of wind power proportion becomes important for ensuring the stable operation of the system frequency and guiding the planning of the wind power supply. This paper presents an analytical method for calculating the ratio limit of wind power considering the primary frequency modulation and the frequency constraints of wind power. By analyzing the response characteristics of the primary frequency modulation of wind power, it points out that the actual increment of the primary frequency modulation power provided by wind power is less than the expected one. In order to accurately calculate the increment of the primary frequency modulation power of wind power, the transfer function model of the primary frequency modulation of wind power is established. The frequency response model of power system considering the primary frequency modulation of wind power is constructed, and the limit value of the wind power proportion under frequency constraints is solved in the analytical method. The accuracy of the proposed analytical calculation of the wind power proportion limit is verified on the MATLAB/Simulink time domain simulation platform.