As an important component of modern transportation, the safe, efficient and stable operation of the energy system in electrified railways is of vital importance. To address the issue of unstable traction network voltage in remote or weak grid areas, an optimized dispatching strategy for the energy management system of electrified railways is proposed on the basis of ensuring the economic stability of the system. Firstly, a system architecture is established based on the four key elements of “source-network-train-storage “. Then, models of each energy unit and an optimization objective model considering both economic cost and traction network voltage are constructed. Finally, the proposed strategy is verified based on measured data, achieving self-contained operation of the electrified railway. The results show that the proposed strategy can not only achieve efficient utilization of new energy but also effectively reduce economic costs or suppress the voltage at the traction network bus. The feasibility of the model and strategy is verified.