Modern warfare modes have given birth to the drone swarms as a new type of operational pattern. The concept of forming the advanced group intelligent behavior obtained by using drones with simple functions

which applies the natural bee swarm organization algorithm

is systematically analyzed. The classification and characteristics of drone swarm are introduced. The key technologies and development status of collaborative networking

sensing

decision-making and control are summarized. Focusing on the practical requirements under complex countermeasure environments

the key points and difficulties in the development of unmanned drone swarm technology which integrates electro-optic detection

communication networking

collaborative control and task planning into one are presented. The development approaches and measures of the drone swarm technologies are also put forward

hoping to achieve the goal of leading the development direction of unmanned drone swarm technology and promoting the corresponding technologies to practical applications.