The mortality rate among patients with secondary infection and severe acute pancreatitis (SAP) remains high.A variety of factors lead to intestinal barrier dysfunction along with bacterial translocation of the intestine,thus making necrotic pancreatic tissue and peripancreatic tissue susceptible to secondary infection.Patients with high-risk secondary infection can be identified through indicators based on patient complications,treatment measures and laboratory tests.For patients likely to have secondary infection,early enteral nutrition and rational use of antibiotics can reduce the incidence of infection.However,probiotic treatments for secondary infections remain controversial regarding their effectiveness and safety.In addition,intestinal decontamination and surgical intervention play important roles in preventing secondary infections.This article summarizes the pathogenesis,risk factors,early diagnosis and preventive methods of SAP secondary infection through reviewing the relevant literature,to provide clinicians with new ideas for diagnosis and treatment.