In order to solve the problems of the traditional text-based research reactor start-up/shutdown plan design method due to the numerous research reactor systems and the complexity of mutual matching interfaces, there are problems such as poor matching of strategies and systems, inter-system interfaces, and difficulty in tracing changes. Model-based systems engineering (MBSE) method, by decomposing demand use cases layer by layer and matching system functions, completes the start-up and shutdown plan design of the research reactor and the design analysis of key equipment maintenance strategy, and uses the simulator to verify the typical operation strategy. The results show that: The start-up and shutdown plan and maintenance strategy can achieve the design goals. The design method is scientific, efficient, and traceable, and can improve the efficiency of nuclear engineering design. Copyright ©2021 Nuclear Power Engineering. All rights reserved.