Objective To study the effect of Low Molecular Weight Heparin Calcium and Edaravone combined with hyperbaric oxygen on severe carbon monoxide(CO)poisoning.Methods A total of 60 patients with severe CO poisoning admitted to Yichun People′s Hospital from January to December 2021 were selected as the research objects and divided into control group and observation group by random number table method,with 30 cases in each group.After admission,patients in both groups were given routine symptomatic treatment such as hyperbaric oxygen and wake-up promotion.The control group was treated with Edaravone on this basis,and the observation group was treated with Low Molecular Weight Heparin Calcium.The clinical efficacy,consciousness recovery time,awake time,incidence of lateonset encephalopathy and changes of hemorheology were compared between the two groups.Results The total effective rate of the observation group was higher than that of the control group,and the difference was statistically significant(P＜0.05).The consciousness recovery time and awake time of the patients in the observation group were shorter than those in the control group,and the incidence of delayed encephalopathy was lower than that in the control group after 3 months of follow-up,and the differences were statistically significant(P＜0.05).The plasma viscosity,whole blood high shear viscosity,whole blood low shear viscosity,hematocrit,erythrocyte deformation index and erythrocyte aggregation index in the observation group after treatment were lower than those in the control group,and the differences were statistically significant(P＜0.05).Conclusion Low Molecular Weight Heparin Calcium and Edaravone combined with hyperbaric oxygen can significantly improve the hemorheological indexes of patients with severe CO poisoning,with short awake time and low incidence of delayed encephalopathy.