Abstract： Objective:To study the clinical value of magnetic resonance diffusion tensor imaging（DTI）in the evaluation of hyperbaric oxygen therapy for cognitive dysfunction in patients with traumatic brain injury.Methods:A total of 106 patients with cognitive dysfunction after traumatic brain injury admitted to the First People’s Hospital of Huzhou from October 2020 to October 2021 were selected as the research subjects and divided into control group and hyperbaric oxygen group according to the random number table method，with 53 cases in each group. The control group was given conventional drug therapy and rehabilitation training，while the hyperbaric oxygen group was given hyperbaric oxygen therapy on the basis of the treatment of the control group. The mini-mental state examination（MMSE）and the Montreal cognitive assessment scale（MoCa）were used to assess cognitive function before and after treatment. The Trail Making Test（TMT）was used to assess the executive function of patients before and after treatment. Before and after treatment，the patients are tested using the Digit Span Test，the Digit Symbol Substitution Test（DSST），and the Exogenous Attentional Orienting Index（E）test.T1WI and DTI scans were performed before and after treatment，respectively，by magnetic resonance diffusion tensor imaging to obtain the anisotropy fraction（FA）values of the left cingulate gyrus，thalamus，inferior frontal gyrus，parahippocampal region，and precuneus regions of the white matter injury areas. Pearson’s correlation coefficient was used to analyze the correlation between FA values and indicators of cognitive dysfunction treated by hyperbaric oxygen therapy for patients with traumatic brain injury.Results:After treatment，the scores of MMSE，MoCA，forward and backward digit span tests，DSST，E，and the FA values of regions in all the white matter injury areas of the two groups were increased，and those scores and values in the hyperbaric oxygen group were significantly higher than those in the control group（ P<0.05 or P<0.01）. Besides，the scores of TMT-A and TMT-B in the two groups were siginificantly decreased compared with those before treatment，and those in the hyperbaric oxygen group were significantly lower than those in the control group（ P<0.01）. There were correlations between FA values and various indicators of cognitive dysfunction treated by hyperbaric oxygen therapy for patients with traumatic brain injury（ P<0.05）. Conclusion:Hyperbaric oxygen therapy can effectively improve cognitive function and attention of patients with traumatic brain injury，and magnetic resonance diffusion tensor imaging has important reference value in evaluating hyperbaric oxygen therapy for cognitive dysfunction in patients with traumatic brain injury，which is worthy of clinical application.