Abstract: Ship electric propulsion has the advantages of high mobility, high efficiency, low vibration and noise, and low energy consumption. It is an important direction for navy and commercial ships, and is widely used in submarines, surface ships, icebreakers, and cruise ships. This paper described the composition of the ship electric propulsion system and the technical index characteristics of the propulsion motors in different configurations of electric propulsion systems. From the perspectives of topological structure, technical points and application in actual ships, the researches of ship electric propulsion motors were reviewed, the key technologies of ship electric propulsion motors were summarized, and the future development direction was pointed out.