Objective To investigate the clinical efficacy of low molecular weight heparin (LMWH)-assisted plasma exchange (PE) in the treatment of patients with hyperlipidemic severe acute pancreatitis (HLSAP).Methods Patients with HLSAP diagnosed and treated in Leshan People's Hospital were retrospectively selected from January 2023 to April 2024 and their clinical data were analyzed.According to the diagnosis and treatment plans,they were divided into the control group (PE) and the study group (LMWH-assisted PE).The coagulation function[fibrinogen (Fib),thrombin time (TT),activated partial thromboplastin time (APTT) and prothrombin time (PT)],plasma specific viscosity,lipid levels[total cholesterol (TC),triglyceride (TG)],inflammatory factors[white blood cell count (WBC),erythrocyte sedimentation rate (ESR),C reactive protein (CRP),amylase (AMY) and lipase (LYP)]were compared before and after treatment between the two groups.The duration of continuous renal replacement therapy (CRRT),length of hospitalization and incidence of new organ dysfunction were compared between the two groups.Results A total of 105 HLSAP patients were included in the study,with 50 in the control group and 55 in the study group.Before treatment,there was no statistically significant difference in coagulation function,lipid levels,plasma specific viscosity and inflammatory factors between the two groups (P>0.05).After treatment,Fib,TC,TG,plasma specific viscosity,WBC,ESR,CRP,AMY and LYP were significantly lower in the study group than in the control group (P<0.05),while TT,APTT and PT were significantly higher than in the control group (P<0.05).The duration of CRRT,hospitalization time and incidence of new organ dysfunction were lower in the study group than in the control group (P<0.05).In terms of adverse reactions,no transfusion adverse reactions and serious complications occurred in both groups during the treatment period.Conclusion LMWH-assisted PE has a better effect in the treatment of HLSAP,which can improve the coagulation function,blood lipid levels and inflammatory factors of HLSAP patients,shorten the hospital stay and the duration of CRRT,and reduce the incidence of new organ dysfunction.