Osteonecrosis of the femoral head (ONFH) is a common and refractory disease. Although it is thought to be associated with circulatory disruption and resultant bone death, its exact pathophysiologic mechanism is not fully understood. Prevention and treatment of ONFH has always been a clinical challenge for orthopedic surgeons. To further standardize diagnosis and treatment of ONFH, the present clinical practice guideline (2020 version) was updated based on "Chinese guideline for the diagnosis and treatment of osteonecrosis of the femoral head in adults (2016)" . The classification system established by the Association Research Circulation Osseous (ARCO) had been widely used in guiding treatment, estimating prognosis, and evaluating efficacy. The ARCO staging system (2019 version) was also introduced in the present guideline. Based on the changes in the intraosseous blood supply at different stages, the corresponding nonsurgical and surgical treatments were recommended. For patients with risk factors for potential ONFH, preventive interventions to avoid the occurrence of osteonecrosis were recommended. New advances in the epidemiology, etiology, pathophysiology, imaging, diagnosis and treatment of ONFH were renewed in this 2020 version guideline. The guideline not only provided primary diagnosis, treatment and evaluation systems for ONFH, but also added some expert advices and consensus, including epidemiology, etiology, diagnostic criteria, pathological staging, prevention, Chinese traditional medicine treatment and postoperative rehabilitation. The guideline provided brief classification criteria and treatment regimen for ONFH. The guideline emphasized the important steps in diagnosis and developing treatment strategies, including specification of the etiology, treatment plan based on comprehensive consideration of the changes in the intraosseous blood supply at different stages of ONFH, hip function, age and occupation of the patients.