As the Passive and Active Hybrid Magnetic Bearing (PAHMB) in a Magnetic Suspended Control Moment Gyroscope (MSCMG) has the dynamic model coupling between the two radial degrees of freedom (DOF), this paper proposes an α-order inverse system method to perform the decoupling control. A radial channel magnetic force model and a dynamic model for the PAHMB magnetic bearing were established based on the structure characteristics of the hybrid magnetic bear.Then,the model was used to analyze the coupling characteristic between the two radial degrees of freedom. In order to obtain the inverse system model of the PAHMB system, the reversibility of the original system was analyzed. The optimal controller was designed to stabilize the new 2-order integral system by consisting of the original system and the inverse system. Experimental results show that when the x-axis is influenced by 40 μm stepping and 18μm sine wave, the y-axis displacement with decoupling method will be controlled 13.6% and 7.9% that with PID method. These results demonstrate the effectiveness of the method above in decoupling control of the PAHMB.