This paper presents a research on a new applicable and effective multi-joint sitting/lying lower limb rehabilitation robot (LLR-Ro). It could help stroke patients recover motion ability of the lower limb. Because of its sitting/lying structural type, it could be used at all the recovery stages, including the initial recovery stage. Based on the ergonomics principle, LLR-Ro with three DOF is developed, which is fully considered the patient’s comfort and compatibility of man-machine. The patients could conduct the rehabilitation training with diversity training trajectories, including the linear trajectory, circular trajectory and arbitrary trajectory.