Abstract: In this paper, the theory and strategy of vibration control for flexible redundant manipulators are firstly studied by the modal theory. On this basis, by analyzing the selection of self motions which meet the need of suppressing vibration, we point out that flexible redundant manipulators still have the second optimization capability at the time of suppressing vibration, then a method for optimizing joint torques on the premise of suppressing vibration is presented. Finally, with this method, simulations of suppressing vibration and optimizing joint torques for a planar three link manipulator with the last link flexible are carried out. The simulation results demonstrate its feasibility.