Knee joint effusion can not be eliminated, if the amount of joint effusion is large can be treated by joint puncture, arthroscopic cleaning and other methods. If there is a small amount of fluid in the knee joint over a long period of time, it usually has little effect on the joint activities and most of them do not need special treatment. In daily life, it is enough to pay attention to proper rest and avoid cold joints. If there is a large amount of fluid in the joint, and the joint is swollen, which affects the knee flexion and extension activities, the fluid can be extracted through joint puncture, and then the elastic bandage can be used to put pressure on the bandage in order to prevent re-exuding. If the long-term joint effusion is large due to knee synovitis or other causes, it can also be treated by surgery, such as arthroscopic synovectomy of the diseased synovium. If the knee joint effusion can not be eliminated, it is recommended that the patient go to the hospital for medical examination to clarify the cause of the disease and receive regular treatment.