Severe geologic disasters can lead to major power outages, affecting the safe and stable operation of power grids. To address the impact of geologic disasters on power grids, a power system security scheduling strategy based on disaster risk mapping is proposed. Firstly, the disaster risk mapping is constructed based on a variety of disaster impact factors, and the hazardous situation of the transmission line can be obtained by combining this mapping with the geographic location of the transmission line; Then, the power system operation risk model is established to quantitatively analyze the risk situation of the power system based on the risk composite indexes; Finally, a particle swarm algorithm is used to construct the regulation strategy of generators and flexibility resources in New England as an example and to verify the effectiveness and feasibility of the strategy. The results show that the proposed power system security scheduling strategy can effectively reduce the value of the comprehensive indicators of risk, including the risk of power system overrun/heavy load, and enhance the security and stability of power grid operation.