Abstract: Multi-motor synchronization systems have been widely used in precision manufacturing. However, it is difficult to design a generalized synchronous control scheme because of the diversity of system structures and the differences in synchronization requirements. To overcome these problems, we establish a generalized dynamic model of plants in multi-motor synchronization systems, which could describe various synchronous control problems in a uniform expression of the mathematical model. Through the kinematics-based coordinate transformation, the complex coupling relationships in the dynamic model are revealed, as well as the formation mechanism of synchronous errors under the coupling effects. The motion decoupling method is proposed, which precisely compensates for differences in dynamic characteristics between the drive-axis and the sync-axis while decoupling the system. Based on the decoupled system, a feedback motion tracking controller is designed to improve the system's real-time synchronization performance. Simulation and experimental results illustrate that the composite synchronous control scheme based on the generalized dynamic modeling analysis, which has good interpretability, can significantly improve the multi-motor synchronization performance.