The harm of osteomyelitis mainly lies in the fact that it may affect children’s growth and development, pathologic fracture and cancer. 1. Affecting children’s growth and development: acute osteomyelitis is mostly seen in children, and the development speed is relatively fast, which often leads to obvious swelling of limbs, and it will develop upward without breaking through the epiphysis, however, it can affect the epiphysis, resulting in slow growth and development of children. 2. Pathological fracture: if it is septic osteomyelitis, it is often caused by bacterial infection, which will lead to the destruction of bone strength, and a slight external force may lead to pathological fracture. 3. Cancer: if it is chronic osteomyelitis, because of long-term stimulation by purulent secretion, it will lead to pathological changes in the surrounding soft tissues, and may cause cancer in a long time. Osteomyelitis is very harmful, once diagnosed, we should actively cooperate with doctors to take standardized treatment.