Knee arthroscopy has been developed in China as a minimally invasive surgery. Its biggest advantage is that it is less invasive, with an incision of only 4 to 6 cm, less painful and easily accepted by patients. The physician can perform dynamic observation during the surgery, clearly understand the condition of the lesion in the knee joint, and accurately remove the intra-articular lesion. However, rehabilitation guidance for patients after knee arthroscopy is an important part of restoring the function of the knee joint. The observation group was given routine functional exercise instruction. For the experimental group, patients were given a systematic rehabilitation program from the time of admission, including muscle strength training, joint mobility training, balance function, and proprioceptive training. The patients were informed of the methods and procedures of postoperative rehabilitation training before the operation so as to obtain the patients’ cooperation. In the experimental group, after the anesthesia disappeared 6h after surgery, patients were instructed to do isometric contraction of the quadriceps and dorsiflexion and plantarflexion of the ankle joint in bed for 30-40 min each time, 3-4 times a day; in the 1st postoperative day, they started to do isotonic exercises, i.e. sitting up and doing knee flexion and extension exercises against the gravity of the lower leg, which should not exceed 90°; in the 3rd day, they started to press the opposite lower leg on the ankle of the affected limb to Increase the resistance of the exercise, the intensity of the exercise 30-40 min each time, 3-4 times a day. During rest, the affected limb can be elevated and ice packs can be applied to the knee joint, usually 20-30 min every 2 h to reduce joint cavity exudation and pain; on the 4th postoperative day, weight-bearing walking can be started twice a day for 10-15 min each time to further strengthen the balance function and proprioceptive training of the lower limb. Endurance training was started 3 weeks after surgery. The bicycle seat was elevated to reduce the flexion of the affected knee, thus reducing the interpatellar force, and it could be performed at fast speed to strengthen the endurance of muscle activity, and also to move the gastrocnemius, hallux valgus, hip and lunguo cord muscles, and then gradually increase the amount of activity in a gradual manner. Patients were instructed to adhere to formal functional exercises within 3 months to maximize the restoration of knee movement and function. Feasibility of early functional exercise Generally, after meniscal injury, the knee joint is in severe pain and cannot be straightened automatically. The symptoms gradually subside after a few days of joint swelling, but the joint always feels unstable in its activities, and there is a popping sound in the joint during activities and pressure pain at the joint space, which affects the patient’s work and life to some extent. Due to the anatomical characteristics of the knee joint, which determines its complexity in biomechanical characteristics such as load motion and stability, patients are bedridden for a long time after surgery, and inappropriate joint braking affects the dynamic balance of the joint aggravating muscle atrophy, which eventually leads to knee instability and even serious complications. However, early postoperative functional exercise and activities can stimulate the synovial membrane to produce high molecular small amounts of hyaluronic acid and promote the recovery of joint function, while early bedtime activities can enhance the patient’s self-confidence, self-care ability and sense of accomplishment, and make them actively participate in treatment care and rehabilitation training. Therefore, systematic functional exercise should be carried out throughout the post-knee arthroscopy period until the recovery of knee function, while also strengthening the proprioceptive function training of the knee joint. Early functional exercise can significantly improve the function of the affected limb Scientific rehabilitation training after knee arthroscopy is essential to obtain the expected efficacy of the surgery. Planned and systematic individualized postoperative rehabilitation guidance for different patients is the key to postoperative rehabilitation training for knee arthroscopy patients. Based on this guideline, early systematic functional exercises were used to help strengthen the knee extension and flexion muscles while minimizing inter-articular patellofemoral pressure. Joint pain and swelling is a common problem after knee arthroscopy, and encouraging patients to move early is bound to aggravate the pain and swelling, causing some concern. Patients in the observation group used conventional functional exercise methods and started functional exercise on the 4th postoperative day with late joint activity. In contrast, the experimental group started functional exercise 6h after the anesthesia disappeared. After each functional exercise in the first 3 d, the affected limb was elevated and an ice pack was placed at the incision site, which could make the local tissue temperature drop and vasoconstriction, thus preventing the formation of hematoma and reducing pain. For patients with severe pain affecting functional exercise, the application of non-steroidal anti-inflammatory drugs is beneficial to reduce pain and inflammatory response. Patients with blood accumulation in the joint can be cured by exercise and elevation of the affected limb to promote self-absorption, and joint aspiration for those who cannot be absorbed. Thus, making no significant difference in the occurrence of postoperative complications between the two groups of patients.