Objective To study value of severe acute pancreatitis (SAP) rat model induced by retrograde pancreaticobiliary duct infusion of methylene blue in combination with sodium taurocholate. Methods The SPF 90 SD rats, 45 male rats and 45 female rats of them, were randomly divided into control group (C group), sodium taurocholate group (ST group) and methylene blue in combination with sodium taurocholate group (MBST group), which were retrogradely infused with the 0.9% normal saline, sodium taurocholate plus DAPI, and methylene blue plus sodium taurocholate plus DAPI respectively into the pancreaticobiliary duct. The success rate of puncture, degree necrosis of pancreas tissue, range of pancreatic lesions, and the incidence of bile or intestinal leakage were compared among the three groups. Results ① The success rate of puncture in the MBST group was significantly higher than that in the ST group (P=0.003) and the C group (P=0.006), which had no significant difference between the ST group and the C group (P=0.782). ② The necrosis degree of pancreas tissues in the MBST group and ST group became more and more severe with the extension of time (P<0.050), which in the MBST group was more serious than that in the ST group (P<0.050). ③ The point of pancreatic lesions range in the MBST group was significantly higher than that in the ST group (P=0.003). ④ The incidence of bile or intestinal leakage in the MBST group was significantly lower than that in the C group (P=0.008) and the ST group (P=0.004). Conclusions Retrograde pancreaticobiliary duct infusion of methylene blue in combination with sodium taurocholate can improve success rate of puncture, aggravate necrosis degree of pancreatic tissue, increase lesion scope of pancreatic tissue, and reduce rate of bile or intestinal leakage, which can provide a stable animal model for basic research of SAP.