The invention discloses a thigh and shank device with a knee joint parameter measurement suitable for an exoskeleton auxiliary supporting robot. The thigh and shank device is characterized in that knee joints are driven by adopting hydraulic cylinders, and the response speed and the bearing capacity of the exoskeleton auxiliary supporting robot are increased; the waist is connected with thighs through telescopic rods, and shanks are connected with feet through telescopic rods; one ends of the hydraulic cylinders are connected with the thighs through supports, pin shafts and joint bearings, piston rod ends are connected with the shanks through hydraulic cylinder connecting pieces, the knee joints are connecting components of the thighs and the shanks, sensors are used for measuring angular displacements of the knee joints, and the moving control that the knee joints of a human body are followed by exoskeletons is realized. According to the high and shank device with the knee joint parameter measurement suitable for the exoskeleton auxiliary supporting robot, disclosed by the invention, only the knee joints are controlled by the hydraulic cylinders, other joints are all used for adapting to moving requirements of leg joints of the human body, and the other joints comprise hip joints which are provided with the sensors, ankle joints, plantar structures, side swinging arms of the waist, globe joints of the thighs and the like; the structural characteristics of the human body are artificially simulated by the exoskeleton auxiliary supporting robot, the thigh and shank device is suitable for the human body to wear, the moving flexibility is maintained, the structure is simple, and a user can be helped to support the load weight.