It can be judged as meniscus injury by the history of knee trauma, clinical symptoms such as pain, popping, sudden jamming during flexion and extension activities, compression pain, etc. Some positive signs will appear in physical examination, and there is clear imaging evidence of meniscus injury in imaging examination. 1. Patients with meniscus injury may have a clear history of trauma, such as knee sprain and sports injuries, and some patients do not have a history of trauma, and there may be occupational and degenerative factors as the basis for the development of the disease. 2. Clinical symptoms: knee pain, inability to straighten the leg, joint popping, sudden jamming of the knee joint in flexion and extension activities. Pressure pain may appear in the joint space. 3. Physical examination: the doctor may show positive signs when doing tests such as McKnight’s test, grinding test, axial shift test, etc., which can be judged as meniscus injury. 4. Imaging: Imaging tests such as MRI can exclude and show the extent and location of meniscus damage. When the above symptoms occur, it is necessary to consult a doctor in time, complete the relevant examinations, make a clear diagnosis and timely treatment.