As a new high speed underwater wireless communication technology, underwater wireless optical communication (UWOC) plays an important role in marine ecological environment monitoring, resource exploration, and military operations, and has become a key technology for competition all over the world. Three kinds of underwater wireless communication modes were compared, the channel characteristics of UWOC were introduced, and the research progress of key technologies such as light source, modulation, channel coding, and detection in UWOC system were described in detail. At the same time, the development trend of UWOC technology was summarized, which provides a reference for further research and practical application of UWOC system in the future.