Abstract: In the fine tracking systems, the amplitude and phase of the beacon light is fluctuated which is caused by the atmosphere turbulence. In order to enhance the tracking system's performance, reducing the facula's vibration induced by the atmosphere turbulence becomes the primary goal, and the fast steering mirror(FSM) is the key instrument to reach that goal. In this paper giant magnetostrictive material（GMM）was used as the offset-generating component of the FSU, which was actuated by the elasticity of the GMM, which was controlled by the magnetic field generated by the current in the coil around the GMM. This fast steering mirror was applied in the tilt correction system for atmospheric laser beam propagation, and the tilt introduced by the turbulent current was reduced by 90%, the stability and concentration of the laser facula was enhanced greatly.