Osteoradionecrosis is a common and severe complication after radiotherapy of head and neck cancer,and it is difficult for clinicians to deal with.The development of osteoradionecrosis is slow and can persist for a long time,and the pathogenesis of osteoradionecrosis is not clear.There is no uniform standard for the treatment of ORN.This review focused on the research advances in the definition,pathogenesis,risk factors,prevention and treatment of osteoradionecrosis.