Ischemic necrosis of the femoral head is a series of pathological changes caused by various causes of insufficient or interrupted blood supply to the femoral head. It occurs from 30 to 60 years old, and is more common in men. The common first symptom is hip pain of different degrees, and about half of them are accompanied by periprosthetic radiating pain. As the periprosthetic pain increases, the affected hip flexion and internal contracture, abduction and internal rotation activities are limited, and the muscle atrophy is advanced. X-ray plain film is the main method for the diagnosis and staging of ischemic necrosis of the femoral head, but it is difficult to show early lesions. CT is better than radiographs in early diagnosis, and is clearer than radiographs in showing hyperplasia, sclerosis, fragmentation and cystic changes in the lesion area. MRI is a more sensitive and specific method to diagnose early necrosis, which can detect lesions before the appearance of X-ray and CT changes, and can directly determine the location and extent of ischemic necrosis of the femoral head in multiple directions, and can make a timely diagnosis for those with negative X-ray and CT examinations.