Abstract: Wind turbines can release kinetic energy of rotors to provide active power to the system, but it may cause a secondary frequency drop when the speed is recovered, which is not conducive to the stability of the system frequency. At present, there are few studies on parameter setting of frequency regulation for wind power considering frequency characteristics in the process of a primary and secondary frequency drop. Therefore, a unified structural model is proposed to approximate the power response of the synchronous machine, wind turbine and other power generation equipment. Based on this, the frequency trajectory of the system is analyzed and frequency characteristics including the average rate of frequency changes, the nadirs of primary and secondary frequency are quantitatively evaluated. Further, considering the two kinds of frequency drops comprehensively, an optimization problem is established to adjust the frequency regulation parameters of wind power with the goal of raising the frequency nadir.Finally, the effectiveness of the proposed frequency characteristic evaluation and parameter setting method is verified by simulations, which shows that the two frequency drop can be increased by setting the frequency regulation parameters of wind power reasonably.