Early active muscle strength training and joint mobility exercise after knee collapse surgery can help the recovery of knee joint function. Generally, 24 hours after knee surgery, patients can carry out maximum static contraction of quadriceps and other lower limb muscles, activate the strength of the affected limb muscles, and move the toes and ankle joints, and gradually increase the strength training of knee flexion and extension movement in the later stage, such as weight-bearing flexion and extension of the knee joint, which will help the recovery of the condition. The exercise of joint mobility can be done by lying on the back with the hip flexed at 90° angle, while the angle of knee extension and flexion can be increased day by day to avoid the occurrence of postoperative complications such as joint ankylosis, flexion contracture and squatting difficulty. Adherence to functional exercise during the postoperative recovery period is crucial, directly related to the patient’s quality of life in the future, rehabilitation exercises need to maintain a good state of mind, strengthen nutrition, pay attention to safety, according to the amount of strength, should go to the rehabilitation department of the hospital to receive regular rehabilitation training. It is recommended that patients consult their doctors in time and carry out rehabilitation therapy under the doctor’s guidance, in order to avoid injuries to the organism caused by improper self-operation.