Abstract: The reliability, availability and safety of signaling system must be maintained at a high level for a robust operating metro system. Therefore it should strengthen the research on making the accuracy and rationality of the maintenance strategy. Through the study of the maintenance activities of signal system, the average reliability and maintenance cost was taken as the optimization target of two-dimensional, the system availability and security were set as the constraints condition of the algorithm, a multi-objective optimization model was built accordingly. The standard particle swarm optimization(PSO) algorithm and the simulated annealing mechanism of particle swarm algorithm were applied to the optimization calculation and result analysis. Finally, the global optimal solution set was obtained to assist decision makers the most favorable maintenance plan.