Abstract: In recent years, with the continuous occurrence of extreme weather and major disasters, such events with low probability and high risk not only caused serious economic losses, but also posed a severe test to ensure the stable operation of the power system. According to different purposes and coping strategies before and after extreme events, it can be divided into prevention strategies before extreme events, response strategies when extreme events occur, and recovery strategies after extreme events. Based on the preventive capability of power system resilience, an index for comprehensive evaluation of preventive capability is proposed, and strategies for effectively improving the system preventive capability are studied on this index. The effectiveness of the evaluation index is verified through the simulation analysis of IEEE 39 nodes. As far as the effect is concerned, the hardware investment strategy can improve the system resilience, but the uncertainty of the investment cost should be considered at the same time.