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A new approach integrating the technique of active vibration suppression and the method of variable structure control is proposed in this paper. In this approach, the technique of active vibration suppression utilizing piezoelectric materials is used to design a controller in the inner feedback loop, which adds damping to the structures in certain critical modes; then an attitude controller is designed by using a variable structure output feedback control strategy in the outer feedback loop to slew the spacecraft and satisfy the pointing requirements. The advantage in this method is that the vibration reduction and attitude pointing are implemented separately in the two separate feedback loops, allowing these two objectives to be satisfied independently of one another. The controller developed is achieved through an adaptive version without the limitation of knowing the bounds of the uncertainties and perturbations in advance. In addition, a modified adaptation control law is also given for the upper bound on the uncertainty to improve the adaptive performances such that a new controller is designed which can guarantee the bound of the closed-loop system and can be described as a combination of sliding mode control law and modification adaptive law. With the piezoelectric actuator/sensor, three effectiveness active vibration control techniques are studied and compared for active vibration suppression. Both analytical and numerical results are presented to show the theoretical and practical merits of this approach.