Craniocerebral trauma causes cerebral edema, ischemia, hypoxia and a series of secondary pathophysiological changes, resulting in reversible and irreversible damage. Hyperbaric oxygen therapy for craniocerebral trauma is to use oxygen to improve the oxygen content of the body so that the damaged tissues and organs can accelerate the reversible recovery under aerobic metabolism. For example, under hyperbaric oxygen, the partial pressure of oxygen in brain tissue increases 7 to 13 times compared with normal pressure, the partial pressure of oxygen in cerebrospinal fluid increases 8 to 14 times, and the partial pressure of oxygen in arterial end of capillary increases 17 to 20 times. The increase of oxygen partial pressure can promote the formation of collateral circulation and protect the ischemic penumbra around the lesion. The cerebral blood vessels contracted and the cerebral blood flow decreased, so that the hypoxic state of the variable hypoxic area of brain tissue was relieved and the cerebral edema subsided. At the same time, the blood flow of vertebral artery increases, which makes the partial pressure of oxygen in the reticular activating system and the brainstem increase relatively, stimulates the excitability of the upward reticular system, and promotes the awakening of comatose people. The treatment of craniocerebral injury can be divided into three phases: acute phase (1 week after the injury), transitional phase (1-2 weeks after the injury), and rehabilitation phase (after 3 weeks). The primary purpose of treatment in the acute phase is to save the patient’s life and to reduce and avoid secondary craniocerebral injuries through emergency surgery and early appropriate medication to improve the patient’s quality of life. For primary brain injury, the main symptomatic treatment is to prevent complications, but the existing medical measures do not change the primary injury. The transition period should mainly pay attention to whether there are new changes in the condition appear, timely treatment, and start rehabilitation. The rehabilitation period is mainly for the rehabilitation of complications and sequelae of brain injury. Because the brain has a very low tolerance to hypoxia, once the injury is localized hypoxia is often more prominent, so early hyperbaric oxygen therapy after the injury can avoid the further damage of hypoxia to the brain cells and reduce the sequelae. In conclusion, hyperbaric oxygen therapy for craniocerebral injury has the advantages of promoting wakefulness, shortening the course of the disease, improving or even eliminating clinical symptoms, reducing sequelae, etc., and should be treated as early as possible. We believe that hyperbaric oxygen therapy can be performed as long as the patient’s vital signs are stable and there are no contraindications to hyperbaric oxygen. Early hyperbaric oxygen therapy can reduce or eliminate various central nervous system dysfunctions caused by hypoxia in brain tissue.