Objective To investigate the effect on intestinal mucosal barrier dysfunction (IBF) of Xuebijing injection mediated by Toll-like receptor 4 (TLR4) signal pathway in rats of severe acute pancreatitis (SAP). Methods 24 Sprague Dawley (SD) rats were randomly divided into Sham group (n=8), control group (n=8) and treatment group (n=8). The SAP model was established by retrograde injection of 4.5% sodium taurocholate into the biliopancreatic duct in control group and treatment group, while control group was injected with the same amount of saline. In treatment group, Xuebijing injection (3 mL/kg) was injected via tail vein after 3h of modeling. All rats were monitored and sacrificed after 24 hours of modeling. Samples of pancreas and intestine were collected for pathologic determination. A fluorescent RT-PCR was used to determine the expression of TLR4 and NF-κB of small intestine. The serum levels of TNF-α, IL-6, amylase (AMS) and diamine oxidase (DAO) were measured by using ELISA. All parameters of three groups were compared. Results The expression of TLR4 and NF-κB of small intestine in control group and treatment group were higher than it in control group (P<0.05), as well as the serum levels of TNF-α, IL-6, AMS and DAO (P<0.05). The expression of TLR4 and NF-κB of small intestine in treatment group were lower than it in control group (P<0.05), as well as the serum levels of TNF-α, IL-6, AMS and DAO (P<0.05). Conclusion Xuebijing injection may not only reduce the expression of TLR4 and NF-κB of small intestine, but also alleviate the inflammation reaction of small intestine by interfering with TLR4 signal pathway, which may have a protective effect on intestinal mucosal barrier in SAP rats.