Abstract: The automatic start-up and shutdown technology used in the reactors can effectively reduce the working intensity of the operators, reduce the misoperation, and improve the safety and reliability of the reactors. Based on the analysis of the process characteristics and the start-up and shutdown operation of a typical pool reactor, this paper researches the control range, hierarchical structure, breakpoints and typical control logics of automatic start-up and shutdown (APS) system in the pool reactor, and completes the simulation and verification system of the pool reactor APS technology. The APS system can achieve the automatic start-up and shutdown, and there is no manual operation in the process, thus reduces the possibility of personnel misoperation.