ObjectiveTo explore whether hyperbaric oxygen therapy(HBO) can promote weight loss and recovery of hyperlipidemia in rats, and to explore the possible mechanism. Methods180 SD rats were divided into 6 groups with 30 rats in each group. The first 3 groups were intraperitoneally injected with fat emulsion to make hyperlipidemia models, and the last three groups were injected with normal saline. The first three groups received 3 h/d, 6 h/d, 0 h/d HBO therapy respectively, and the last three groups received the same treatment. Body weight, blood lipid and transaminase were measured in all SD rats, and pathological sections of heart, liver and kidney were observed. ResultsHyperlipidemia group treated with 3 h/d hyperbaric oxygen has the effect of reducing hyperlipidemia compared with other groups and has the effect of heart and kidney protection. Although 6 h/d HBO therapy has a more noticeable effect on lowering hyperlipidemia, it has more apparent liver damage effects. The normal group treated with HBO for 3 h/d or 6 h/d both have the effect of weight loss, and the impact of liver injury is not apparent. However, the 6 h/d HBO therapy group had a more prominent weight loss effect. ConclusionHBO therapy can promote weight loss and reduce hyperlipidemia. Our experiments have shown that 6 h/d and 3 h/d HBO therapy reduces blood lipids in hyperlipidemia SD rats. However, the former has noticeable liver damage effects on SD rats, and the latter is adequate for protecting the liver in normal or hyperlipidemia SD rats. At the same time, it has been proved that HBO therapy has cardio and kidney protection in hyperlipidemia SD rats.