Second, hypoxic encephalopathy and its brain dysfunction 1, brain dysfunction after cardiopulmonary resuscitation: cardiopulmonary function is often restored after successful resuscitation of cardiac arrest, brain function is severely damaged, and the patient is in a continuous coma, which is a common cause of death after resuscitation. Literature reports and clinical experience show that patients in cardiac arrest, within 5-6 minutes of effective cardiopulmonary resuscitation, respiration, heartbeat recovery, despite the critical condition, after hyperbaric oxygen therapy will significantly improve brain dysfunction, and even successful brain resuscitation. It has also been reported that the overall efficiency of receiving hyperbaric oxygen therapy after successful cardiopulmonary resuscitation is significantly better than that of patients who did not undergo hyperbaric oxygen therapy, and the earlier the time of hyperbaric oxygen therapy, the better the clinical effect. 2. Asphyxia (hypoxic): Like other hypoxic encephalopathies, patients with asphyxia who are resuscitated and transferred to our department have different degrees of impaired consciousness, inability to eat, incontinence, often accompanied by infection, bed sores, choking and dystonia. Our hyperbaric oxygen department mainly treats patients with hypoxic encephalopathy and ischemic diseases, and is the first in the country and abroad. Our team has rich experience in medical care, and hyperbaric oxygen therapy can effectively improve the level of consciousness and quality of life of asphyxiated patients. It has been reported that hyperbaric oxygen can promote the recovery of brain cell function, reduce cerebral edema and decrease the occurrence of sequelae in asphyxiated patients, and the efficiency of hyperbaric oxygen therapy can be increased by 16％ compared with that without hyperbaric oxygen therapy. 3.Acute craniocerebral trauma: Traumatic brain injury includes severe craniocerebral injury, cerebral contusion, diffuse axonal injury, subdural hematoma and epidural hematoma, etc. Traumatic brain injury is a common cause of death and disability in people under 50 years old. Hyperbaric oxygen therapy has the effect of promoting neural repair and reducing cerebral edema, which can promote the recovery of consciousness and reduce the rate of disability. After the disease is stabilized, conditions should be created to provide hyperbaric oxygen therapy as soon as possible. In the past 20 years, our department has cured numerous patients, and the literature reports that the total efficiency of hyperbaric oxygen therapy can reach 90.5％.