Meniscal injuries are one of the most common injuries of the knee and are closely related to its anatomy and are prone to occur in a variety of sports. There are four conditions that must be present to produce a meniscal injury: adduction or abduction, knee hemi-flexion, gravitational compression and rotational forces. There are two types of external forces: lacerative and abrasive. Acute injury is mostly tearing external force, and long-term squatting, kneeling work, because the meniscus long-term grinding extrusion by the joint surface, accelerate the degeneration of the meniscus, the meniscus chronic tearing injury, this is no clear trauma can also appear meniscus injury reason. Meniscus injury can appear pain, swelling, locking, muscle atrophy and other four major clinical symptoms, “locking” phenomenon is seen in patients due to partial tearing of the meniscus, often the torn barrel handle part of the sandwich in front of the femoral condyles, need to be slightly shaken or change position after “unlocking The patient needs to be “unlocked” after a little shaking or change of position in order to extend and flex or stride. However, in the elderly, strangulation may also be caused by intra-articular free bodies or osteoarthritis. MR has the advantages of non-invasive simplicity of operation and high accuracy, high resolution of muscles, tendons and cartilage, multi-directional and multi-parameter, and has an important value in the diagnosis of the degree of meniscal injury. Generally speaking, for degree II meniscal injury, which is mainly a sign of meniscal degeneration, most patients can take conservative treatment, such as herbal fumigation and ultrashort wave therapy, etc. For degree III injury of the meniscus, basically It can be confirmed that there is a tear and requires surgical intervention. It is worth mentioning that MR results are correlated with the diagnostic level of the person reading the film. In clinical cases requiring arthroscopic surgical treatment, physicians should combine clinical symptoms and physical examination and make careful judgments. Arthroscopic surgery is a minimally invasive procedure, and there are generally no major risks in experienced hospitals. The hospitalization period is about 3-4 days, and most patients can resume self-care after awakening from anesthesia.