Abstract: In this paper,the mathematical model of inverse dynamic control of flexible robot arms is analyzed.Theiterative algorithm of inverse dynamic problems,that is,the method of errors compensation of the dynamicposition and orientation is put forward successfully,with which the driving torque and joint variables for ob-jective position and orientation can be calculated off-line or in real-time.The simulation results show that thismethod has the advantages of less amount of calculation and higher accuracy.In the same time,this paperpresents a hierarchical control system which incorporates organically two functions:dynamic feedforward-servo compensation and vibration suppression control with torque feedback.