Abstract: Rehabilitation robots have played an increasingly important role in improving the quality of life of patients with limb movement disorders and the elderly. In this paper, a solution and the corresponding cable force optimization and control strategy of the cable-driven parallel rehabilitation robots to assist patients in lower limb rehabilitation training are proposed. For the multi-solution problem of cable force optimization, in this paper the alternative objective function is introduced when the cable force changes abruptly. On the basis of analyzing the patient's traveling intention, different auxiliary functions will be realized according to the patient's different traveling intention. Based on Euler-Lagrange method, a dynamic model of a parallel robot with eight cables and six degree of freedom is constructed, and a proportional differentiation (PD) feedback controller is designed. The effectiveness of the dynamic model, cable force optimization and control method is verified by numerical simulation.