Meniscus injury is a common knee disorder, the normal meniscus is composed of fibrocartilage and appears uniformly black in MRI. According to MRI images, meniscal injuries can be classified into three degrees: degree I, degree II, degree II, degree II, degree III, degree III, degree III, degree III, degree III, degree III, degree III, degree III, degree III, degree III, degree III, degree III, degree III, degree III, degree III, degree III, degree III, degree III, degree III, degree III, degree III, degree III, degree III, degree III, degree III. In degree I meniscal injuries, the lesion area shows limited mucocutaneous degeneration, vitreous degeneration and chondrocyte reduction under microscopy. It appears as a mass-like signal within the meniscus on MRI. In degree II, which is a progression of degree I, collagen fragments are visible microscopically, with transverse fibers penetrating the collagen bundles in the middle portion of the meniscus. It shows a linear abnormal signal on MRI. Degree III is a severe progression of degree II, where trauma is the precipitating cause of meniscal tears, and in younger patients, where there are no significant degenerative changes in the meniscus, trauma is the direct cause of meniscal injury. On MRI, the abnormal signal appears as parallel, oblique, stellate or irregular shape, but its distal reach to the articular surface is the main basis for the diagnosis of meniscal tears. In general, it can be considered as follows: Grade I signal is a degenerative signal. grade II signal is more degenerative. grade III signal represents a torn meniscus injury, and the following are the common types of tears. Treatment: Grade II injury is an expansion of grade I injury, usually in grade I injury fails to heal in a timely manner, due to its improper care resulting in the expansion of the injury, the tear extends to the bloodless area resulting in increased pain and difficult recovery, but in the bloodless area tear is small there is still hope for recovery through conservative treatment. The clinical results are good. The meniscus will have a certain impact on the stability of the knee joint and the knee joint will degenerate faster after the meniscus is removed, but the results are much better than those obtained by delaying the treatment. It is also the main treatment modality for Grade III injuries.