Abstract： AIM:To discuss hyperbaric oxygen(HBO)for traumatic subdural effusion(TSE)genesis,development impact,as well as HBO on the TSE therapeutic effect and to analyze its mechanism.METHODS:To add up the total incidence rate of TSE after craniocerebral injury;To compare the incidence of TSE bewteen earlier HBO therapy treatment after injury(group A)and without HBO treatment(group B);To compare the clinical prognosis between HBO therapy treatment for earlier discoverable TSE (group C)and without HBO treatment(group D);To compare curative effect between trepanation and drainage+HBO therapy treatment(E group)and simple trepanation and drainage treatment(F group)for TSE of operative indication.RESULTS:The total incidence rate of TSE after craniocerebral injury is 7.35%.Its incidence rate of A group is 3.99%and that of B group is 6.90%,these two group have significant difference(P<0.01).The total effective and healing rate of C group is 90.91% and 52.12%,but that of D group is only 77.86% and 24.43%,these two group have significant difference(P<0.01).The total effective and healing rate of E group is 93.10% and 45.98%,but that of F group is 80.77% and 28.85%,these two group have significant difference(P<0.05).CONCLUSION:HBO therapy Call validly prevent the incidence of TSE and have obvious therapeutic efficacy for it,and it should be considered a conventional therapy method for TSE.