Abstract： Objective:To explore the the effects of hyperbaric oxygen（HBO）therapy at 0.20 MPa and 0.25 MPa on the prognosis and oxidative stress levels of patients with traumatic brain injury.Methods:The clinical data of 52 patients with traumatic brain injury admitted to the Rehabilitation Center of the Fuxing Hospital，Capital Medical University，from January 2017 to December 2019，were collected. According to the random number table method，the patients were divided into control group and observation group，with 26 cases in each group. The control group received HBO therapy at 0.20 MPa，while the observation group received HBO therapy at 0.25 MPa.The serum oxidative stress index levels were compared between the two groups after treatment. Before treatment and three months after treatment，the Glasgow coma scale（GCS）was used to assess the patient’s state of consciousness，and the Glasgow outcome scale（GOS）was used to evaluate the prognosis.Results:After treatment，there was no statistically significant difference in serum oxidative stress index levels between the observation group and the control group（ P>0.05）. After treatment，the GCS scores of patients with moderate to severe conditions in both groups were all significangtly increased（ P<0.05 or P<0.01），while the improvement was not significant in patients with mild conditions（ P>0.05）. Compared with the control group after treatment，the GCS scores of patients with severe condition in the observation group significantly improved（ P<0.05），while there was no significant improvement in patients with mild to moderate conditions（ P>0.05）. The ratio of patients with good prognosis in the observation group（80.77%）was significantly higher than that in the control group（53.85%），and the GOS scores were also significantly higher in the observation group than those of the control group（ P<0.05）. Conclusion:The treatment protocol of 0.25 MPa HBO demonstrates better clinical effects and prognosis in treating patients with severe traumatic brain injury，without aggravating the oxidative stress response，thus ensuring higher safety. Patients with mild to moderate traumatic brain injury can choose the treatment protocol of 0.20 MPa HBO.