Objective To investigate the effect of a citrate dialysate contains no calcium in the continuous blood purification treatment of critically ill patients.Methods A retrospective analysis was performed on 88 patients with severe disease who received continuous blood purification treatment and needed anticoagulation with citrate from April 1,2018 to December 31,2019.According to the different use of dialysate,the patients were divided into study group(calcium-free dialysate containing citrate)and control group(traditional dialysat containing calcium).The hemofilter life and the changes of coagulation function,acid-base electrolyte,liver and kidney function were compared between the two groups.Results After treatment,there were no statistically significant differences in the changes of acid-base electrolytes,liver and kidney functions,and coagulation indexes between the two groups(P>0.05).The hemofilter life was(30.0±10.93)h in the study group and(24.3±8.19)h in the control group.The hemofilter life was prolonged by the use of anticoagulation with the citrate dialysate contains no calcium(P=0.039).The variation of venous pressure per hour and transmemtal pressure per hour in the dialysis machine were 1.9(1.5,2.5)mmHg,and 5.2(3.9,6.7)mmHg in study group.In control group,the variation of venous pressure per hour was 2.8(2.3,3.7)mmHg,and that of transmemtal pressure per hour was 8.7(6.0,9.1)mmHg.There were statistically significant differences in unit time pressure changes between the two groups(P<0.05).The vital signs of all patients were stable during the treatment,and no obvious complications such as hypotension and bleeding occurred.Conclusion Compared with the traditional dialysa containing calcium citrate in blood purification,the new citrate dialysa contains no calcium can not only achieve the therapeutic effect,but also delay the pressure rise of the hemofilter and prolong the hemofilter life.It is a safe and effective method for critically patients.