Firstly，the practical significance of underwater electromagnetic detection technology is elaborated. Then，the research status of underwater electromagnetic detection and early warning system abroad is introduced， as well as the performance indexes of electric field sensors and magnetic field sensors. Based on the analysis of the development process of domestic underwater electromagnetic detection technology and the gap with technologies of foreign countries，the development trends of integration，intelligence，systematization，unmanned，diversification and networking of underwater electromagnetic detection system in the future are pointed out.