Abstract: With the rapid development of deep space exploration and space infrastructure construction, the on-orbit assembly of ultra-large space structures has been recognized as a critical research area in the aerospace engineering. Autonomous on-orbit assembly technology based on modular spacecraft clusters through rendezvous and docking is systematically overviewed in this paper. The paradigm shift from human-assisted assembly to autonomous cluster assembly is first reviewed, along with technical characteristics of representative international on-orbit assembly projects. Advancements in six-degree-of-freedom modeling for rigid spacecraft and rigid-flexible coupling dynamics for flexible spacecraft are summarized, and the applicability of the floating coordinate formulation, absolute nodal coordinate formulation, and geometrically exact method is comparatively analyzed for diverse systems and operational scenarios. Task and path planning strategies for spacecraft clusters based on graph search, tree search, and reinforcement learning are discussed. Key control technologies, such as trajectory tracking control, inter-satellite collision avoidance control, and vibration suppression control, during the assembly process are introduced. The limitations of ground experiment methods (e.g., water flotation and air bearing) are critically assessed, while the potential of digital twin technology for virtual-physical fusion testing is highlighted. Finally, future research directions are proposed in the field of system dynamics, autonomous assembly planning, spacecraft control technologies, and ground-based experimental verification.