Objective: To observe the treatment effects of hyperbaric oxygen on severe acute mountain sickness (ASHS) integrated with multiple organ dysfunction syndromes (MODS). Methods: 2006-2010 admitted to two hospitals in the Tibetan Plateau, 66 cases of patients who got the severe acute mountain sickness complicated by MODS were divided into two groups, 28 cases in the conventional therapy group, 38 cases in hyperbaric oxygen treatment therapy group, oxygen therapy, the conventional therapy concluded oxygen therapy, the treatment of primary disease and enhance the support for treatment of metabolic; hyperbaric oxygen group (was) on the basis of conventional therapy and hyperbaric oxygen therapy was used, the clinical effect of those two groups were compared with; with measured the before and after treatment blood levels of cytokines, to investigate the therapeutic mechanism of hyperbaric oxygen therapy. Results: The efficacy of hyperbaric oxygen treatment group and the treatment time are better than the conventional treatment group, hyperbaric oxygen treatment significantly reduced TNF, IL-6, IL-8 levels, and there is a significant difference between before and after treatment. Conclusion: the method of Hyperbaric oxygen for acute high altitude mountain disease complicated with MODS is reliable and had notable curative effect.