The number of patients with lower limb dysfunction is increasing day by day, and the technology of lower limb rehabilitation robot is also improving. Lower limb dysfunction will seriously affect the quality of life of the patients. The reasonable application of lower limb rehabilitation robots can effectively improve the symptoms of the patients, achieve accurate rehabilitation, and make the rehabilitation strategies more optimized. In this paper, the key technologies and equipment characteristics of different lower limb robots are described, combined with the research status at home and abroad. The clinical effect of lower limb robot is analyzed in different joints and diseases. Finally, the future development of lower limb rehabilitation robot is summarized and prospected.