Abstract: Unlike that in the onshore nuclear power plant, the refueling operation in the floating nuclear reactor will be affected by the wave environment, so new requirements for refueling operation technology and equipment are put forward. In this paper, the refueling scheme of Marine Nuclear Power Platform is selected to simulate the process of fuel assembly entering the reactor core under rocking condition. The analysis results show that the fuel assembly meets the strength design requirements in the process of introducing universal joint fuel assemblies entering the reactor core.