Elimination image rotation subassembly is an important part of panorama electro optic systems,the stability and accuracy is an key index of the servo control systems. This paper described the formula derivation of the shafting resonant frequency based on the multi body dynamics theory,and got the calculating result by dint of the ADAMS soft. The sweep frequency result indicated that the theory is correct. This result would help to offer the credible basis for the servo control systems design,and availably shorten the development periods.