Treatment of osteoarthritis is divided into conservative treatment and surgical treatment. Conservative treatment is based on systemic medication and intra-articular local medication. In early stage OA patients, oral anti-inflammatory and analgesic drugs or drugs that activate blood circulation and resolve blood stasis can be given symptomatically to improve symptoms and quality of life. Intra-articular injection of hyaluronic acid, a joint cartilage protector, has certain effect. For OA patients with significant joint pain, swelling, walking dysfunction, MRI showing cartilage destruction, intra-articular free bodies, bone growth or with meniscal damage, they should resort to surgery. Surgical methods for the treatment of OA include arthroscopic cleanup, drilling and decompression microfracture in the area of total cartilage damage, high tibial osteotomy with corrective force lines, and artificial joint replacement. The application of chondrocyte transplantation, growth factors and gel carriers are in the research and trial stage. Arthroscopic cleanup can be performed with epidural anesthesia or local anesthesia. Local anesthesia is applied with 2% lidocaine 20ml + saline 40mm + 0.1% epinephrine solution 0.1ml as a mixture, which is injected into the surgical entrance and joint cavity respectively for local infiltration anesthesia, and the procedure can be performed after 10 minutes. To maintain a clear intraoperative field of vision, saline 3000ml + 0.1% epinephrine injection 1ml as perfusion solution can be dispensed with for surgery under tourniquet control. Arthroscopic examination is performed sequentially to obtain a comprehensive understanding of the intra-articular lesion and to perform arthroscopic surgery. Osteoarthritis is an age-related, degenerative change, and no method can stop aging. It is not possible to reverse the degeneration of the joint that has developed. It is possible to clean and repair the unstable cartilage trauma, release the blockage and impact of the motion trajectory, and remove the pain-causing factors, cartilage degradation particles, macromolecular components, debris and microcrystals of the worn out articular cartilage, inflammatory factors and pain-causing substances from the joint, which is conducive to functional recovery. The factors of poor postoperative efficacy are not only the heavy degeneration of articular cartilage at advanced age, but also the change of force line in the lower limb of internal and external knee deformity, which is directly related to the size of surgical trauma. Therefore, we advocate selective and limited minimally invasive cleanup under local anesthesia arthroscopy without excessive interference with intra-articular tissues. Postoperative ice packs applied cold to the affected knee for 24-48 hours can achieve hemostasis and pain relief. In cases of significant postoperative swelling, blood and fluid should be aspirated from the joint cavity, and intra-articular injection of sodium hyaluronate should be performed 7-10 days later. Postoperative functional exercises for the quadriceps muscle of the knee are beneficial for functional recovery.