Objective To investigate the main risk factors that influence lifespan of the extracorporeal circuit device in continuous renal replacement therapy （CRRT） without anticoagulation, to provide evidence for nursing risk assessment of non-anticoagulant CRRT. Methods A retrospective analysis was performed to enroll 257 patients with acute renal failure or chronic renal failure and at high risk of bleeding.The patients were admitted to hospital from July 2015 to July 2018, and underwent first time non-anticoagulant CRRT treatment. Results A total of 125（48.64%） experienced extracorporeal circuit device failure during non-anticoagulant CRRT and lifespan of extracorporeal circuit device averaged (248.51±87.56)min. Multivariate Cox proportional hazards regression model analysis showed that four independent factors were associated with extracorporeal circuit device lifespan significantly respectively: frequency of pump interruption due to poor blood flow （HR=1.572,95%CI=1.373-1.801）,the volume ratio of venous chamber embolism （HR=1.022,95%CI=1.014-1.030）, hematocrit （HR=1.037, 95%CI=1.007-1.068）, and the dose of CRRT （HR=1.336,95%CI=1.007-1.772）. Conclusion Such factors as frequent pump interruption due to poor blood flow, high volume ratio of venous chamber embolism, high hematocrit values, and high-dose CRRT were significantly associated with the lifespan of extracorporeal circuit device during non-anticoagulant CRRT.During the therapy, intermittent flushing with saline could not extend the lifespan of extracorporeal circuit device.Clinical workers should take interventions targeting the risk factors, so as to reduce the incidence of extracorporeal circuit device failure, extend lifespan of the device, and ensure the safety of treatment.