Abstract: Unmanned swarm system is the focus of military research at home and abroad in recent years, which is promoting the transformation of unmanned combat style from “single platform remote control warfare” to “intelligent swarm warfare” of sea, land and air cooperation. In this paper, the latest research progress of unmanned swarm system at home and abroad in recent years is reviewed, including exploration and practice of autonomous collaboration technologies of unmanned system in military industry, national defense and academic circles. Then, the key technologies of unmanned swarm system are introduced, including autonomous collaboration of multi-agent system, situation consensus of multi-agent system, unknown system dynamics, swarm intelligence theory and technology, machine learning methods, behavioral decision-making methods, experimental scenario simulation and so on. Finally, the technical characteristics, challenges and development trends of di erent key technologies are analyzed.