Knee popping is a common clinical problem, knee popping is generally divided into physiological and pathological causes, as follows: 1, physiological popping: because the gas and liquid in the normal joint to a certain concentration, with the joint mobility and position change, so that the joint cavity pressure changes, and then make the already saturated gas and liquid concentration changes, and then the bubble rupture and cause a popping, is generally Physiologically there is no harm and no pain, so there is no need to do special treatment for this kind of ringing; 2, pathological ringing: because of lesions around the knee joint or even within the knee joint, caused by a kind of ringing, this ringing is usually accompanied by pain, and in the process of special parts and position transformation, ringing and pain, it is recommended to regular hospital treatment, because it may be seen in the meniscus of the knee joint Injuries to the meniscus, anterior and posterior cruciate ligaments of the knee, cartilage injuries of the knee, and even free bodies of the knee joint require professional treatment or even surgery.