The invention relates to a wearable lower limb exoskeleton rehabilitation robot. A hip joint component comprises a motor, a harmonic reducer and an output shaft, wherein the motor is connected with the output shaft by virtue of the harmonic reducer, the output shaft is connected with thigh components by virtue of keys, and motor torque is transmitted. The two thigh components are connected together by virtue of a mooring rope passing through a back component, and gravity center shift in a walking process is utilized for helping bulking and extension of each hip joint. The bulking and extensionof each hip joint are driven by adopting the motor and are helped by adopting the mooring rope, and the structure not only reduces weight of an exoskeleton but also converts potential energy of the gravity center shift in the walking process of a human body into kinetic energy of thighs swinging forward, so that energy loss is effectively reduced, and power consumption of the motor is reduced. Each knee joint is designed to be a four-bar mechanism, the stability of a standing phase and the flexibility of a swinging phase are guaranteed. A knee-ankle linkage mode enables a wearer to naturallybuckle the knee joints when swinging and automatically lock the knee joints when standing. A gas spring mechanism is adopted for providing help for conversion of sitting and standing postures.