Emergency shutdown is the automatic action of safety protection to immediately shut down the reactor in order to reduce or prevent the danger state when the event that endangers the safety of the reactor occurs. Emergency shutdown of the reactor is one of the important functions in the protection and safety monitoring system. This article investigates the emergency shutdown plan for the steam and power conversion system in a nuclear power plant. By establishing a model for simulation calculation, problems were identified in the initial plan. And after optimizing the plan, simulation calculations were conducted again. The simulation calculation results show that the optimized scheme meets the design requirements. The article provides important theoretical support for analyzing and evaluating the feasibility of an emergency shutdown plan for a nuclear power plant, which is of great significance for ensuring the safe and reliable operation of the plant.