Objective To observe the clinical curative effect of Depmas double blood purification system for acute severe organophosphorus pesticide poisoning.Methods Retrospectively study was carried out on 147 patients of acute severe organophosphorus pesticide poisoning.Patients were divided into four groups,the conventional treatment group treated with drug therapy,hemoperfusion group given HA230 hemoperfusion in addition to conventional treatment,plasma exchange combined with hemoperfusion group given HA230 hemoperfusion and plasma exchange therapy in addition to conventional treatment,and Depmas group treated with plasma separation by Baxter blood fiber and then given series HA230 and BS330 hemoperfusion treatment on the separated plasma in addition to conventional treatment.Survival rate,mean survival time of death patients,the concentration changes of cholinesterase and bilirubin in peripheral blood were observed.Results Compared to the conventional treatment group,survival rates of hemoperfusion group,hemoperfusion combined with plasma exchange group and Depmas group were higher,the mean survival time was longer,the cholinesterase concentration in peripheral blood was higher and the elevated bilirubin concentration was decreased with the differences statistically significant (P＜0.01).Compared to hemoperfusion group,the survival rates of hemoperfusion combined with plasma exchange group and Depmas group were higher,the mean survival time was longer,the cholinesterase concentration in peripheral blood were higher and the elevated bilirubin concentration was decreased with the differences statistically significant (P＜0.05).Besides,there were no significant differences between the survival rate,mean survival time,peripheral blood cholinesterase and bilirubin concentration of hemoperfusion combined with plasma exchange group and that of Depmas group (P＞0.05).Conclusions Depmas dual blood purification system has remarkable curative effect for the treatment of acute severe organophosphorus poisoning.