Knee joint replacement can be exercised in the following ways: 1. Exercise of knee joint range of motion: active flexion and extension of the knee joint should be started after the knee joint replacement surgery when the swelling and pain symptoms are reduced, or passive flexion and extension activities can be assisted by a rehabilitation doctor to ensure that the knee joint is flexed and extended several to dozens of times a day, so that the knee joint can be bent to a normal level and fully straightened within 2 months. The active contraction, diastole and resistance training of the above muscles can enhance muscle strength and intensity, restore the stability of the knee joint, accelerate blood circulation in the lower limbs, prevent deep vein thrombosis, promote the swelling of the knee joint, and improve the stability of the knee joint, so that the patient can resume normal life and work as soon as possible. Normal life, work, and even normal sports can be resumed.