Abstract: In recent years, the technologies of maritime Unmanned Vehicle (UV) have developed rapidly, and especially because the development of artificial intelligence technology, it has made great breakthroughs in the functions and performance of the maritime UV. The development status of the maritime UV technology at home and abroad is reviewed, and then the key technologies for the maritime UV are analyzed. On this basis, a set of classification criteria for the intelligent levels of the maritime UV is proposed, and the operational capabilities and characteristics of the UVs at different intelligent levels are defined in detail, and the key technologies for evolution between levels are clarified. This provides a theoretical basis for the development of the maritime UV.