Hyperbaric oxygen therapy for patients with ischemic necrosis of the femoral head is intended to treat osteonecrosis by increasing the oxygen content in the blood through pressurization and increasing the blood oxygen content in the femoral head, thereby improving the hypoxic environment in the femoral head. However, the problem is that osteonecrosis is the occlusion of capillaries in the femoral head, the gradual disappearance of bone trabecular structures and the capillaries between them, and blood cannot enter the femoral head normally. Hyperbaric oxygen therapy for osteonecrosis, because the red blood cells carrying oxygen cannot enter the femoral head, even if we do hyperbaric oxygen therapy, oxygen cannot enter the femoral head, and also various nutrients cannot enter the femoral head, and at the same time, the metabolites in the femoral head cannot be discharged in time, forming a vicious circle, and the osteonecrosis keeps getting worse. Therefore, hyperbaric oxygen treatment methods are unlikely to improve the hypoxic environment within the femoral head. Although some benefit is envisaged, it will not play a fundamental therapeutic role. Clinically, cases of ischemic necrosis of the femoral head cured by hyperbaric oxygen therapy alone are very rare.