1.Functional exercise Arthroscopic surgery has the characteristics of early functional exercise to promote functional recovery and shorten the course of the disease. Functional exercise can prevent joint cartilage and soft tissue adhesions, prevent muscle atrophy, enhance muscle strength, promote blood circulation in the affected limb, and facilitate the decreasing of edema and effusion. Functional exercise should be different from person to person, not fatigue is appropriate, gradual and persistent. 2, early out-of-bed activities and weight training Arthroscopic surgery generally advocates early out-of-bed activities, the first day after surgery to start partial self-care, such as washing face, brushing teeth, etc.. 5 days after surgery, you can walk on the ground without weight-bearing with the help of crutches, and after 1 week, you can change to partial weight-bearing of the affected limb, and after 3 to 4 weeks, you can reach full normal weight-bearing. 3, muscle training (1) ankle and toe flexion and extension exercises 12h after surgery, the affected limb fixed to do the ankle joint toe flexion and extension at a uniform rate for 1 group of exercises. 8-10 groups/min, 3-5min each time, 3-4 times a day. To promote blood circulation, reduce the swelling of the affected limb and prevent deep vein thrombosis. (2) Quadriceps isometric contraction training starts 1 day after surgery, the affected limb is fixed, the patient lies on his back or sits down, the knee is straightened, the thigh muscle is tensed, and it is effective to feel the patella slide up and down. 3~5 groups/min, 10~20 min each time, 3~4 times a day. To promote blood circulation and reduce swelling and pain. (3) On the second day after surgery, the patient lies on his back with the knee joint on the healthy side flexed, the knee joint on the affected side straightened and the ankle joint in a functional position, and raises the affected limb to a height of 10-20 cm, 10-20 min each time, 2-3 times a day. (4) On the second day after passive training, start passive knee flexion 2 to 3 times a day and gradually increase the range of motion to prevent adhesions. On the third postoperative day, joint mobility exercises were started under the guidance of the physician, generally starting with 30 degrees of knee flexion, twice a day for 60 min. depending on the patient’s tolerance, the range of motion was increased by 10-15 degrees per day, so that the passive knee flexion reached 90 degrees in the first postoperative week and 100-110 degrees in the second week. 4. Precautions Do not stop exercising or over-exercise after discharge. Usually pay attention to the knee joint to keep it warm and elevate it at night to facilitate blood circulation. Review regularly at the hospital for professional guidance.