The unmanned system cluster is an important key technology that determines the future of urban intelligence and military modernization. Complex and unpredictable mission scenarios require platforms of mission execution units capable of rapid emergency changes, which is the distinguishing feature of the heterogeneous platform intelligent cluster technology. This special issue "Unmanned Intelligent Cluster" comprehensively reviews the various new technologies involved in unmanned clusters, which help to understand the full picture of unmanned cluster applications in urban logistics, factory inspection, security of key locations, and other military and civilian fields. In response to the rapid and dynamic changes in the complex urban environment and military scenarios, unmanned cluster technologies accomplish task collaboration and information sharing among multiple platforms through rapid task allocation, real-time planning, multi-target perception, identification and tracking. The latest research examples in the special issue will demonstrate possible new application scenarios and future research directions of unmanned cluster technology.