Abstract: The satellite is a typical system that was the characteristic of an alterable structure, a configuration, the parameter and centroid when its large antenna is deploying. In order to satisfy the requirement of the control system at both the appendage and overall spacecraft levels, a loaded mode synthesis-hybrid coordinate method is applied to build the flexible coupling dynamic equations for the deploying of large antenna, and the whole satellite flexible coupling dynamic equations with any configuration are obtained by a component mode synthesis. The simulation example and the test of the inertial completion show that the results are practicable and effectual.