With the deepening implementation of major aerospace projects, large and complex spacecraft are evolving toward larger scales, higher performance, and multi-payload integration, leading to increasingly complex on-orbit dynamics issues. This study focuses on the field of dynamics for large and complex spacecraft, systematically reviewing the research team's technological breakthroughs and engineering practices during the 13th and 14th Five-Year Plan periods of China. Driven by the engineering application demand for typical payloads such as large deployable antennas, laser communication terminals, and large optical cameras, key technologies were addressed, including nonlinear modeling and model reduction for flexible dynamics of large-aperture annular antennas, high-fidelity modeling and efficient simulation of on-orbit deployment dynamics for large space structures, micro-vibration assessment of high-precision and high-stability payloads under multi-source disturbances, rigid‒liquid‒flexible coupled dynamics modeling and simulation, and system-level thermal deformation modeling and simulation. An integrated simulation software system for the dynamics of large-scale complex spacecraft, with independent intellectual property rights, was developed. These achievements have been successfully applied in the engineering development of satellites with large deployable antennas, high-resolution optical remote sensing systems, and inter-satellite laser communications, and have been validated through ground tests and on-orbit flight experiments. Furthermore, considering the needs of current engineering development for large and complex spacecraft and the future development of new spacecraft, technical research directions in system design, dynamics and control, verification, and prediction are outlined. The relevant content are expected to provide references for guiding spacecraft design and on-orbit operations, as well as addressing future dynamic challenges in complex space systems.