Osteonecrosis of the femoral head (ONFH) presents a rapidly progressive natural disease course. Femoral head collapse may occur within two years, ultimately necessitating total hip arthroplasty and imposing a heavy medical and economic burden on patients. Early intervention can significantly improve the long-term prognosis of ONFH. However, due to the lack of validated biomarkers for early diagnosis, the early diagnostic rate remains low, with a primary diagnostic rate of merely 68.43% at the first visit, accompanied by a high rate of misdiagnosis. This project intends to collect blood samples from patients diagnosed with ONFH and suspected cases in the orthopedic outpatient department of a tertiary Grade A hospital. Diagnostic and differential diagnostic tests will be adopted to evaluate the clinical application value of previously reported candidate biomarkers, so as to screen out biomarkers with excellent diagnostic validity and reliability. Meanwhile, clinical data will be collected to identify independent risk factors, and a multi-dimensional integrated diagnostic model will be further established. The research findings are expected to provide solid data support, theoretical basis and technical reserves for the early prevention, early diagnosis and individualized intervention of osteonecrosis of the femoral head.