Abstract: Due to the lack of time and limited communicative capacity during operation, the nuclear pow-ered ship requires more concise and accurate event reporting capability than common nuclear power plants, which ensures the actual conditions of the marine nuclear power plant can reach multiple parties quickly. This paper focuses on the events reporting problem of marine nuclear power plants: by combining with the mature experience of the international nuclear and radiological event scale(INES), a unified system of rules is established, and the classification standards helping different parties to realize the severity of nucle-ar events are formed. The research work is of great significance to the safety assurance of marine nuclear power plants.