Abstract： Objective:To analyze the effect of hyperbaric oxygen (HBO) combined with large bone flap decompression in the treatment of craniocerebral injury and its influence on the prognosis of cognitive function.Methods:A total of 108 patients with craniocerebral injury admitted to the Neurosurgery Department of Anyang People′s Hospital from the June of 2015 to the December of 2017 were selected and divided into control group and observation group, with 54 cases in each group. The control group was given the modified large bone flap decompression and other conventional symptomatic and supportive treatments. The observation group was treated with HBO on the basis of the treatments of the control group. The clinical efficacy of the two groups was compared after 3 courses of treatment. The peak systolic velocity ( Vs), mean velocity ( Vm) of blood flow, and pulsatility index (PI) of the middle cerebral artery were measured by transcranial doppler, the intracranial pressure and arterial partial pressure of oxygen (PaO 2) were observed, and the levels of serum Tau protein and glial fibrillary acidic protein (GFAP) were detected. The Neurobehavioral Cognitive Status Examination (NCSE) was used to assess the effect on the prognosis of cognitive function. Results:After 3 courses of treatment, the total effective rate of the observation group (83.33%) was significantly higher than that of the control group (62.96%) ( χ2=8.585, P<0.05). In both groups, Vs, Vm, and PaO 2 significantly increased, and the PI and intracranial pressure significantly decreased. Regarding the improvements of these indicators, those of the observation group were better than those of the control group, with statistically significant difference ( P<0.05). The levels of serum Tau protein and GFAP in both groups decreased, and the levels in the observation group were significantly lower than those in the control group ( P<0.05). Cognitive function scores in both groups increased, and the score of the observation group was significantly higher than that of the control group ( P<0.05). Conclusion:HBO combined with large bone flap decompression treatment can perceptibly improve the cerebral blood flow, reduce the levels of serum Tau protein and GFAP, promote the nerve functional recovery, and improve the cognitive ability, which is worthy of popularization and application in clinic.