Abstract: In order to have a comprehensive understanding of research and development of visual navigation technology in aircraft fields,the key technologies of visual navigation are analyzed.Three technologies are systematically expatiated, including the methods for obtaining the aircraft attitude from the sensors image,the positioning methods based on image matching algorithms,and the velocity measurement technology based on image sequence.The relationship between attitude and reference features,the core algorithms of scene matching for position and the two methods for velocity measurement are mainly discussed.The related difficulties and trend in the developing of visual navigation are also summarized.