The knee joint is the most extensive and complex of the joints in the human body, and also forms the largest synovial cavity, which is most vulnerable to injury due to the heavy load and movement of the knee joint. The synovial membrane is mainly distributed around the joint, communicating with the joint cavity and secreting lubricating fluid to lubricate the joint. Common causes of synovitis include osteophytes, arthritis, tuberculosis, rheumatism, and traumatic trauma, bone injury, intra-articular injury, peripheral soft tissue injury, surgery, etc. The main clinical manifestations: joint congestion and swelling, pain, increased exudation, joint effusion, difficulty in moving and squatting, and limited function. Synovitis is an aseptic inflammatory disease caused by poor microcirculation, and the main symptom is the production of fluid. However, we should pay attention to minimize the frequency of pumping injections, because too many pumping injections can stimulate the fibers of the subsynovial connective tissue group to proliferate and the synovial tissue to age, which will significantly reduce the regeneration and repair ability of the synovial tissue and make the treatment more troublesome. The bursa is a reservoir of oil, which is used to fuel the movement of the skeletal tendons, the purpose is to increase lubrication and reduce friction, if there is fluid, the fluid diluted synovial fluid will not play a lubricating role, at this time, strenuous activity will produce skeletal friction and eventually damage the bones. Current treatment methods for joint effusion 1, etiological treatment If it is caused by infection, it should be combined with systemic or local medication to fight infection. If the recurrent joint effusion is caused by metabolic diseases, active medical treatment should be carried out for the main diagnosis, such as gouty arthritis, which can significantly relieve joint effusion after active anti-gout treatment and joint cavity cleaning. 2, Chinese medicine surgical plaster paste can penetrate into the skin to produce anti-inflammatory, pain relief, blood circulation, meridians, open and penetrate the bone, dispel wind and dispel cold. The plaster applied to the body surface stimulates nerve endings, dilates blood vessels through reflex, promotes local blood circulation, improves nutrition of surrounding tissues, and achieves the purpose of swelling, anti-inflammation and analgesia. 3.Rest, less activity, do not deliberately bend the knee joint 4.Physical therapy