Low altitude flying objects have been widely used in many fields, bringing a lot of convenience to society, and have important strategic significance in both military and civilian fields. However, low altitude flying objects often pose a significant threat to the safety of low altitude areas in low altitude environments. In recent years, the number of accidents caused by drones has been increasing. In recent years, low altitude target detection technology has received increasing attention from researchers and has made significant progress in various research methods. It is urgent to conduct a systematic review of effective detection technologies for low altitude targets. This article provides a comprehensive overview and analysis of the latest progress in low altitude target detection. Initially, it outlined the contemporary research landscape, including various detection technologies such as radar, radio, and vision. Subsequently, a thorough review and analysis of these methods were conducted, and the main challenges in this field were explored. Finally, the discussion integrates key insights and insights drawn from the discussion.