Compared with traditional thermal power systems participating in frequency regulation, utilizing the wind-Thermal-storage joint system for frequency regulation has natural advantages in wind power absorption, energy conservation and emission reduction. However, the uncertainty and volatility of wind power pose challenges to the strategy formulation of wind-Thermal-storage joint system in participating in frequency regulation. Therefore, this article proposes an optimization strategy for wind-Thermal-storage joint system participating in frequency regulation based on robust model predictive control. Firstly, based on the working principle of wind-Thermal-storage joint system participating in primary frequency regulation, a frequency regulation framework containing RMPC based controller was constructed. Then, establishing the response models of wind, thermal, and energy storage, taking into account multiple constraints including operating limits of each component and power balance in primary frequency regulation of the system, a two-layer robust optimization model was built to minimize the frequency regulation cost of the system under the maximum uncertainty of wind power output. After that, to accelerate the model solution, the strong duality theory was used to achieve the single-layering of the min-max two-layer robust optimization model and the uncertainty constraints of wind power output and load fluctuation were linearized. Finally, several cases were carried out in MATLAB/Simulink to verify the effectiveness of the proposed optimization strategy which can significantly improve the frequency regulation effect.