Abstract: In this paper reaction wheels inner friction and static and dynamic imbalance are particularly analysed by reaction wheels dynamics. A mathematical model is set up. A method of control disturb is used. for example, the method to estimate the inner friction torque is introduced by using compensation observer, and the method to estimate the wheel static imbalance and dynamic imbalance is introduced by using late and forward revise compensation. And the numerical simulation model is constituted. Finally, the simulation results prove that this method can improve satellite attitude pointing accuracy and stability efficiently.