Chitosan injections are closed injections, mainly used to treat arthritis, which can be effective. It is also used to repair surgical wounds and prevent post-operative organ adhesions. Chitosan is a polysaccharide polymer extracted from the shell of marine crustaceans, which can regulate the immune function of human body, strengthen cellular immunity, enhance the activity of macrophages, and also has certain anti-cancer effect. It can also promote physiological repair of postoperative tissue wounds and reduce scar production. Clinically, joint cavity closure injection with chitosan can treat osteoarthritis and also intra-articular cartilage damage. It mainly uses the drug to treat the repair function of the joint cavity and immune regulation. A slight pain may occur after the injection, and most of them can recover on their own within a week. At the same time, oral medication for arthritis, such as clozoxazone tablets, diclofenac sodium, ibuprofen, etc., should be taken under the guidance of a doctor, and gradual functional exercises can help recovery. In addition, chitosan is also widely used in surgery. Whether it is laparoscopic surgery or general surgery, the intra-abdominal wound is coated with chitosan after surgery, which can play a barrier role to promote wound healing and prevent adhesions between the wound and the organs in the abdominal cavity.