In order to effectively adjust and control the motion amplitude of the flexible manipulator and avoid large deviation between the actual motion track of the flexible manipulator and the target track，a flexible manipulator motion track control system based on the combination of distributed control system （DCS） and inertial weight was designed. It is a computer system that integrates computer，communication，display and control and is controlled by process control and process monitoring. The DCS algorithm was used to control the behavior amplitude of the monitored object and calculate the inertia weight of the flexible manipulator. The DCS-inertia weight combination was used to solve the specific value of the prime control index. The software design of the flexible manipulator motion trajectory control system was realized. The experimental results show that the motion amplitude of the end coordinates of the manipulator in the horizontal，vertical and spatial axes under the action of the DCS-inertia weight combination algorithm can be controlled within 10 units of length，and the optimal control state of the manipulator's motion trajectory can be entered within 0.52 s，with the maximum difference of the motion trajectory being only 0.01 rad，which verifies the feasibility and effectiveness of the system.