Abstract: For the lack of man-machine interaction and rigid-flexible coupling caused by heavy load in the current heavy load manipulator control system, a force/position closed-loop control algorithm for man-machine interaction based on dynamic model is proposed, and a control system of 7 DOF (degree of freedom) heavy load manipulator is designed according to the algorithm. Firstly, the working characteristics and problems of the existing heavy load manipulators at home and abroad are analyzed. And a man-machine interaction mode based on force/visual feedback is proposed to enhance the interaction performance of the system. In order to restrain the control problem caused by rigid-flexible coupling, a rigid-flexible coupling dynamic model of the heavy load manipulator is established, and a force/position closed-loop control algorithm for heavy load manipulator based on man-machine interaction is proposed. Finally, a control system of heavy load manipulator is set up, which consists of man-machine interaction subsystem, environment perception subsystem, driving subsystem, information processing subsystem and communication subsystem. On this basis, the operation test of the heavy load manipulator control system is carried out. The test results show that the control system can complete the function of man-machine interaction. Compared with the traditional working method of heavy load manipulator, the proposed system can effectively improve working efficiency by 70%, and ensure the safety of operating personnel. It is proved that the proposed control system is user-friendly, feasible and practical.