Objective To investigation the efficacy and safety of prolonged intermittent renal replace-ment therapy(PIRRT)to substitute for maintenance hemodialysis(MHD).Methods Clinical data of the pa-tients treated with renal replacement therapy in the 940th Hospital of Joint Logistics Support Force of Chinese PLA between Oct.2022 to Mar.2023,at which quarantine procedures were carried out for the epidemic of coronavirus 2019 disease,were retrospectively studied.The patients undergoing pre-and post-dilution of ac-celerated venovenous hemofiltration(AVVH)were divided into two groups according to the dialysis dose:low-dose group[25~30mU(kg.h)]and high-dose group[50~60ml/(kg·h)].Treatment parameters for the first PIRRT,serum levels of urea,K+,PO4 and carbon dioxide at the beginning and end of PIRRT,estimated urea reduction rate(URR),spKt/V,and complications occurring during and after PIRRT were collected and compared between the two groups.Results There were no significant differences in age,sex ratio,dry body weight and hemoglobin(t=1.388,0.459,0.479 and 0.913 respectively,P=0.085,0.498,0.683 and 0.818 re-spectively)between low-dose group(n=31)and high-dose group(n=36).Blood flow rate of PIRRT,treatment dose and filter fraction were significantly higher in high-dose group than in low-dose group(t=14.535,39.358 and 7.304 respectively,P<0.001);while total net ultrafiltration had no difference between the two groups(t=1.076,P=0.857).Serum K+,PO4,and carbon dioxide were corrected to normal ranges at the end of PIRRT in both groups.URR and spKt/V were significant higher in high-dose group than in low-dose group(t=12.039 and 5.145,P<0.001).No complications were observed during and after PIRRT.Conclusions PIRRT can effectively correct volume overload,electrolyte abnormalities and acid-basc imbalance.High-dose PIRRT is more effective than low-dose PIRRT in removal of uremic toxins,and is well tolerated by the patients and suitable to substitute for MHD.