Abstract: After sufficient literature survey and summary, a comprehensive and systematic analysis on the current water-air amphibious trans-media unmanned vehicle is conducted, and a survey on this kind of unmanned vehicle is completed from the view of the overall unmanned aerial vehicle (UAV) field. The existing water-air amphibious trans-media unmanned vehicles are divided into three categories, i.e., the seaplane UAV, the submarine-launched UAV, and the submersible UAV, and then the typical prototypes of each category are reviewed. Subsequently, the general issues and transition modes between media in which each type of vehicle moves are discussed.