Unmanned aerial vehicle autonomous navigation system is the core of unmanned aerial vehicle to realize intelligent flight, and is a hot field of UAV technology research. For unmanned aerial vehicle autonomous navigation system, the basic concept and development history are introduced, three key technologies, namely high-precision positioning technology, multi-source information cooperative processing technology and intelligent path optimization, are refined, the current development status and existing problems of several key technologies are analyzed, and the future development trend of unmanned aerial vehicle autonomous navigation system is prospected.