To solve the problem of dynamic coupling between satellite platform and antenna system, a three degree of freedom drive and measurement mechanism was utilized to interface antenna arm and satellite platform, and to control pointing of antenna. By this mechanism, the drive torque was fed forward into attitude control system to compensate reacting torque and realize decoupling control between satellite attitude and antenna pointing. Dynamic model of satellite platform and antenna with decoupled mechanism was established for large angle attitude maneuver. Using this model, large angle maneuver control law was designed and simulation was done for performance verification. Results demonstrate that the decoupling control approach could increase the stability of satellite attitude with two orders of magnitude. Decoupling control enhances vibration damping and improves satellite stability.