Bone marrow edema of the knee joint is an imaging change on MRI, and is most often seen in cases of knee trauma, where local trauma has caused bone damage, but has not yet caused a fracture. In this case, there is a clear history of trauma, and this bone marrow edema can be treated with oral medication such as blood-activating and pain-relieving capsules and appropriate rest and recuperation. In addition, local osteomyelitis of the knee joint and bone tumor may also have such manifestations, which are accompanied by clinical manifestations such as local fever, generalized hyperthermia and local pain, while the bone tumor also has abnormal manifestations such as local masses. For bone marrow edema caused by osteomyelitis, appropriate restriction of knee joint activities, timely antibiotics, such as levofloxacin injection and other anti-inflammatory treatment, local magnesium sulfate can be applied topically. If it is caused by bone tumor, surgery is usually required.