Abstract: Energy storage system has a flexible regulation performance. It will improve the frequency stability combining energy storage and the wind turbine to participate in the primary frequency regulation. As energy storage is currently expensive, it is necessary to take into account the cost of frequency modulation. Therefore, an optimal control strategy based on the model predictive control is proposed to improve the effect of frequency modulation and realize the optimal distribution from the perspective of economy. Firstly, a prediction model is established according to the state equations of the system. Then, the constraints of the wind turbine and energy storage and the power balance constraint are considered. With the minimum frequency modulation cost as the optimization goal, the changes of the pitch angle of the wind turbine and the changes of energy storage are controlled. Finally, the validity of the proposed strategy is verified on the MATLAB/Simulink platform. The results show that this strategy not only has a better frequency modulation effect than the traditional PI control, but also realizes the optimal allocation of the wind turbine and energy storage power based on the economic benefit during the frequency modulation process.