Abstract: The principle of coarse and fine combined stabilization control system for optoelectronic stabilization platform was introduced. Two assumptions of the systematic model were proposed according to the different structures of the fast steering mirror (FSM). Based on the two assumptions, the frequency character and stability of system were deeply analyzed. Results show that the performance of the combined stabilization control system is mostly depended on the bandwidth ratio of the major to the sub-system and the choice of the combined controller K.