Abstract: Objective To explore effect of hyperbaric oxygen combined with vitamin C in the treatment of patients with acute carbon monoxide poisoning(ACOP)and its effects on myocardial markers and antioxidant levels. Methods According to the random number table method, 46 patients with ACOP were divided into two groups, with 23 cases in each group. The control group was treated with hyperbaric oxygen, while the observation group was additionally given vitamin C on the basis of the control group. The total clinical efficacy, the levels of creatine kinase isoenzyme(CK-MB), brain natriuretic peptide(BNP), cardiac troponin I(cTnI)before and after treatment, catalase(CAT)and serum lipid peroxide(LPO)before and after treatment were observed. Results The total effective rate in the observation group was 95.65%, which was significantly higher than 73.91% in the control group(P<0.05); the levels of CK-MB, BNP and cTnI in the observation group were significantly lower than those in the control group(P<0.05); levels of LPO and CAT after treatment in the observation group were significantly lower than those in the control group(P<0.05). Conclusion Hyperbaric oxygen combined with vitamin C in patients with ACOP can improve the efficacy, reduce free radicals, and shorten the length of hospital stay.