Objective To investigate the effect of hyperbaric oxygen treatment on course of different intervention time,cognitive impairment in patients with traumatic brain injury.Methods Ninety cases of cognitive dysfunction in patients with traumatic brain injury after hyperbaric oxygen in different intervention time were divided into group A,group B and group C,with 30 cases in each group.In 7-14 d,15-28 d,＞ 28 d after injury starting hyperbaric oxygen therapy,treatment 1 time a day,12 times for a course.The cognitive function of patients in three groups before and after 1,2,3 courses of treatment was evaluated by U.S.RLA cognition level classification standard evaluation form.Results Three groups after 1 course of treatment there was no statistically significant difference compared with before treatment RLA grading (P ＞ 0.05).Three groups after 2,3 courses of treatment compared with after 1 course of treatment RLA grading difference was statistically significant (P ＜ 0.05),three groups after 3 courses of treatment compared with after 2 courses of treatment RLA grading difference was statistically significant (P ＜ 0.05).Three groups after 1 course of treatment total effectiveness rate was no statistically significant difference(P ＞ 0.05).Group A and group B after 2,3 courses of treatment total effective rate was significantly higher than that in group C [73.33％ (22/30) and 66.67％ (20/30) vs.46.67 ％(14/30),93.33％ (28/30) and 86.67 ％(26/30) vs.60.00 ％ (18/30),P ＜ 0.05],group A was higher than group B,but there was no statistical significance (P ＞ 0.05).Conclusions Hyperbaric oxygen comprehensive therapy can effectively improve cognitive function in patients with traumatic brain injury cognitive impairment.After the injury,the earlier to start the hyperbaric oxygen therapy,the better effect it has,and the longer the course the better curative effect it has.