Abstract： Objective： To observe the clinical effect of external application of Natrii Sulfas combined with retention enema with Rhei Radix et Rhizoma for severe acute pancreatitis (SAP). Methods：A total of 144 cases of SAP patients were selected and divided into the routine group and the combination group according to the random number table method，with 72 cases in each group. The routine group was given routine treatment， and the combination group was additionally treated with external application of Natrii Sulfas combined with retention enema with Rhei Radix et Rhizoma based on the treatment of the routine group. Both groups were treated for 7 days. The time of bowel sounds recovery， abdominal distension relief and total hospital stay，as well as the levels of amylase (AMS)，lipase (LPS)，interleukin-6 (IL-6) and procalcitonin (PCT) in serum were compared between the two groups. Results：The time of bowel sounds recovery， abdominal distension relief and total hospital stay in the combination group were shorter than those in the routine group， differences being significant (P＜0.05). After treatment， the levels of AMS， LPS， IL- 6 and PCT in serum in the two groups were decreased when compared with those before treatment，and the levels of AMS，LPS，IL-6 and PCT in serum in the combination group were lower than those in the routine group， differences being significant (P＜0.05). Conclusion： External application of Natrii Sulfas combined with retention enema with Rhei Radix et Rhizoma for SAP can relieve clinical symptoms，and reduce levels of AMS，LPS，IL-6 and PCT in serum.