A six degree-of-freedom (DOF) Stewart platform is constructed, which consists of six TbDyFe alloy magnetostrictive actuators, and applied to active vibration control. To control the smart structure, a real time computer control system is built. An improved adaptive filtering algorithm is proposed in this paper, which is used for the computer control system. The results of experiments show that the smart structure and the proposed algorithm are efficient for active vibration control. More than 30 dB of vibration attenuation is achieved in real-time experiments.