Abstract: High fire accuracy is one of performance goals of MultipleLaunch Rocket System (MLRS). One of effective methods to improve the fireaccuracy with low cost is the vibration control of launcher in MLRS. In thispaper, transfer matrix method of multibody system (MSTMM) is used to developdynamical model of MLRS. Active vibration control law is designed for pulsethruster using quadratic performance index as cost function. In the law, thepulse thruster is taken as an actuator for launcher vibration control.Vibration control system of MLRS launcher is established under the impact ofgas jet from rocket motor. A numerical simulation example on vibrationcontrolling of MLRS launcher is given to obtain optimum amplitude of pulsecontrol force and working times of pulse thruster. Numerical results ofcontrolled and uncontrolled vibration response of launcher show that controllaw in this paper is efficient to reduce launcher vibration. Furthermore,the present method in this paper is easy to realize in practicalengineering, and it is important to be used to control launcher vibration soas to improve fire accuracy of MLRS.