Lower limb rehabilitation robot is a rehabilitation training tool for lower limb dysfunction, which can provide safe and effective walking training for patients with walking dysfunction caused by nerve injury. The structure and function are the key factors that affect the functional recovery of the patients. Therefore, the systematic summarization for structure and function of the lower limb rehabilitation robot can provide important reference for structural optimization and function enhancements. The classification, driving mode and clinical application of  lower limb rehabilitation robot are reviewed in this paper, and the research direction in future of lower limb rehabilitation robot is prospected.