Septic osteomyelitis is a relatively common inflammatory lesion in clinical practice. It can be primary, that is, hematogenous osteomyelitis, or it can be a bone infection due to trauma or some other cause. The main manifestations on X-ray are as follows: 1. Bone destruction due to bacterial retention and inflammatory reaction, which can be large or relatively limited in scope. Therefore the bone destruction shows a tendency of destruction on X-rays, showing a hypodense presentation. Inside the area of destruction, large or small pieces of dead bone can also be observed, that is, images of free bone. And around the area of destruction, we can also see an obvious progressive osteosclerosis, that is, the closer to the necrotic area, the higher the degree of sclerosis, and the more scattered outside the necrotic area, the lower the degree of sclerosis; 2. Due to the inflammatory reaction and stimulation, an obvious periosteal reaction can be caused. However, most of the periosteal reactions are relatively regular and polished; 3. The swelling of the surrounding soft tissues and even the formation of abscesses can be observed.