Abstract: To comprehensively evaluate the impact of renewable energy and seasonal hydrogen storage on regional energy system planning,and alleviate the seasonal contradiction of energy supply,the paper proposes a regional energy system optimization model considering the seasonal hydrogen storage. Firstly,according to the historical data from renewable energy generation output,the K-means clustering method is employed to generate typical output scenarios,and an extreme scenario with a certain confidence level is introduced to ensure the robustness of the model. Then considering the energy technologies such as power to hydrogen and the seasonal hydrogen storage as well as various constraints in both planning and operation stage,an regional energy system optimization model is established with the goal of minimizing the total cost of the energy supply system,giving full play to the complementarity of different forms of the energy in multiple scenarios and time scales. Finally, case studies are given to verify the effectiveness of the proposed model in reducing the cost of the energy supply and integrating the renewable energy.