Abstract: Extreme meteorological disasters are easy to cause large area fault of transmission network. The health degree of transmission network equipment affects the physical ability of transmission network to resist extreme meteorological disasters. In order to further enhance the transmission network disaster resistance ability and reduce economic losses, this paper studies the pre-disaster preventive maintenance strategy of transmission network from the connotation of transmission network resilience improvement. In this paper, firstly, disaster risk resilience is proposed as the evaluation index of transmission network disaster resilience, and the scenario analysis method is used to calculate the resilience index according to the spatial and temporal characteristics of extreme disasters. According to the requirements of toughness improvement, maintenance risk and economy of transmission network pre-disaster preventive maintenance, a multi-objective and multi-stage optimization model of transmission network pre disaster preventive maintenance is proposed, and the solution is solved by combining NSGA-II algorithm and mathematical programming solver. The effectiveness of the optimization model is verified by IEEE RTS-79. The example results show that the proposed optimization model can obtain Pareto frontier and the optimal compromise solution, and the optimal pre-disaster preventive maintenance plan can be obtained accordingly, which can improve the disaster resilience and control the risk and cost of pre-disaster preventive maintenance, so as to help power grid operators make scientific decisions, and has good application value.