With the onset of winter, the number of patients suffering from carbon monoxide poisoning (commonly known as gas poisoning) is gradually increasing. Hyperbaric oxygen therapy has been recognized as the treatment of choice for the rescue and treatment of patients with carbon monoxide poisoning and late-onset encephalopathy. The principle of hyperbaric oxygen therapy is: hyperbaric oxygen rapidly increases the partial pressure of blood oxygen and oxygen concentration, so that the tissues get enough dissolved oxygen, promote the elimination of carbon monoxide, restore the oxygen-carrying function of hemoglobin, and improve the oxygen deficiency of the body. At the same time, it can lower the intracranial pressure, reduce cerebral edema and promote the recovery of brain function. Hyperbaric oxygen therapy for carbon monoxide poisoning has the following advantages: one fast (fast recovery from sobriety), two high (high cure rate, high total efficiency), three less (less complications, less toxic encephalopathy, less death).