A Fast Steering Mirror (FSM) suitable for motion environments was designed to control the laser beam stabilization and its accurate alignment for a laser projecting system in the vibration and shocking. According to the requirement of performance of the optical system, the necessary physical and mechanical characteristics of the FSM were presented for the reflecting mirror of a high energy laser. The voice coil actuators with large travels were used as the drivers of the FSM, and angle displacement measuring devices with high precision and anti-jamming ability were taken as the position sensors of the FSM. The four voice coil actuators and four angle position measuring devices were reasonably arranged to decrease the inertial moment of the system and also to improve the reliability and condition adaptability. The experimental result shows that the positioning accuracy of FSM is better than 1.4″, which satisfies the precision requirement of the laser projecting system for the FSM.