In order to solve the problem of FROG-LEG vacuum manipulators’dynamic compensation,based on its structure,the dynamics in the level and upright direction was discussed, respectively, by using New-Euler method to give dynamics equations.Rotor flux oriented of PMSM was analyzed,which was the dynamic source of vacuum manipulators.Robot tool of MATLAB was utilized to simulate the kinematics and dynamics of vacuum manipulators,proving that dynamic current feed forward compensation is an effective way to realize vacuum manipulators’smooth control.