Objective To explore the effect of backflushing with ultrapure dialysis fluid in patients on heparin-free hemodialysis.Methods A convenience sample of 45 patients at risk for bleeding receiving heparin-free hemodialysis were divided into a control group （n=26） and an intervention group （n=19）.During hemodialysis, the control group used normal saline for flushing, while the intervention group received intermittent backflushing with ultrapure dialysis fluid.The completion of treatment, coagulation parameters and convenience of nursing operation were compared between the two groups.Results Both groups received 91 sessions of hemodialysis.The rate of completion of the treatment after early termination of hemodialysis sessions or replacement of the tubing system, and the rate of clotting at the dialyzer and venous drip chamber were significantly lower in the intervention group than those in the control group (all P＜0.05). The intervention group also had significantly shorter duration of each dialysis session and fewer nursing operations compared with the control group (both P＜0.05).There were no statistically significant differences in coagulation parameters pre- and post-dialysis in the intervention group (all P＞0.05).However, in the control group, the prothrombin time and activated partial thromboplastin time were significantly prolonged, and the fibrinogen level was significantly reduced (all P＜0.05).Conclusion Backflushing with ultrapure dialysis fluid can effectively reduce extracorporeal circuit clotting in patients receiving heparin-free hemodialysis, thereby improving hemodialysis efficiency and safety.