The increasing use of unmanned aerial vehicles(UAVs) poses great threats to public security and personal privacy. Therefore, the counter UAV(c-UAV) has became a very important emerging field in recent years. To ensure national defense security, public safety and personal privacy, more and more researchers hope to better counter UAV through more accurate UAV detection and tracking technology and introducing new functions and new concept technologies. This survey summarizes the progress of c-UAV technology at home and abroad, which may help make recommendations and improvements of c-UAV applications for the future. Related researches on UAV detection and classification methods using radar, electro-optical, thermal, and acoustic sensors as well as multi-sensor information fusion algorithms have been thoroughly reviewed in this paper. Afterwards, the composition of the c-UAV technology system and the advantages and disadvantages of related systems are reviewed. At the same time, the c-UAV technology, the well-known c-UAV system and the UAV cluster countermeasure technology are discussed. Finally, we look forward to the research prospects in the field of c-UAV. These work will lay a foundation for solving the low altitude safety problem.