The battlefield threat posed by of unmanned aerial vehicles (UAVs), especially small unmanned aircraft systems (UAVs), are increasing day by day, and have even become a pivotal element capable of altering the course of warfare, gaining asymmetric advantages on the battlefield, which brings an urgent need of counter-small Unmanned Aircraft System (C-SUAs). Major military powers around the world have intensified their investments in counter-small UAV operations, initially developing a certain level of counter-small UAV confrontation capabilities. Based on the analysis of UAVs and the requirements of counter-small unmanned aircraft warfare, the system framework, the technologies and the development status of C-SUAS are summarized in this paper, and the trend of development of C-SUAS is discussed as well. The findings are intended to provide guidance for the development and construction of C-SUAS in the future and to support counter-small unmanned aircraft warfare.