In order to achieve precise damage to target by shipborne laser weapon in complex combat environment,a primary-precise compounded stabilized platform based on fast steering mirror is proposed to control the stabilization precision of laser beam transmission.First,the composition of the system and the working principle are introduced,a fully flexible fast steering mirror driven by piezoelectric ceramic is designed,and the performance characteristics of the fast steering mirror is analyzed.Then the primary-precise compounded control system is designed,on this basis,the interaction factors between the components of the primary-precise compounded stabilized platform is discussed.Finally,the error transfer function of the primary-precise compounded control system is deduced by theoretical calculation,and an experimental platform is set up to test the stabilization precision.The experimental results indicate that,in swaying state of the four level sea condition,compared with the traditional primary stabilized platform,the stabilization precision of the azimuth compounded platform is about 27.6 times increased from 191.6μrad to 6.7μrad,the stabilization precision of the pitching compounded platform is about 23.8 times increased from 121.3μrad to 4.9μrad.In the conditional of external disturbance,the stabilization precisions of the laser beam controlled by the primary-precise compounded stabilized platform are no more than 10μrad.It can satisfy the operational requirements of the high stabilized precision laser beam controlled by shipborne laser weapon platform.