Evidence suggests that Dachengqi and its modified decoctions are effective for treating abdominal pain, multiple organ dysfunction syndrome (MODS) and inflammation in various disease conditions. We performed a meta-analysis to ascertain the effectiveness of a series of chengqi decoctions in patients with severe acute pancreatitis (SAP).We searched Pubmed, Embase, Cochrane library, Web of Science, Chinese National Knowledge Infrastructure, Chinese Biomedical Literature, Wanfang database and China Science and Technology Journal Database before August 2022 to identify eligible randomized controlled trials (RCTs). Mortality and MODS were chosen as primary outcomes. Secondary outcomes included time until relief of abdominal pain, APACHE II score, complications, effectiveness, IL-6 and TNF-α levels. The risk ratio (RR) and standardized mean difference (SMD) with a 95% confidence interval (CI) were selected as effect measures. The quality of evidence was independently assessed by two reviewers using Grading of Recommendations Assessment Development and Evaluation (GRADE) system.Twenty-three RCTs (n = 1865) were finally included. The results showed that, compared with routine therapies, chengqi-series decoctions (CQSDs) treatment groups were associated with lower mortality rate (RR: 0.41, 95%CI: 0.32 to 0.53, p = 0.992) and incidence of MODS (RR: 0.48, 95%CI: 0.36 to 0.63, p = 0.885). They also reduced remission time of abdominal pain (SMD: -1.66, 95%CI: -1.98 to -1.35, p = 0.000), complications (RR: 0.52, 95%CI: 0.39 to 0.68, p = 0.716), APACHE II score (SMD: -1.04, 95%CI:-1.55 to -0.54, p = 0.003), IL-6 (SMD: -1.5, 95%CI: -2.16 to -0.85, p = 0.000), TNF-α (SMD: -1.18, 95%CI: -1.71 to -0.65, p = 0.000), and improved curative effectiveness (RR:1.22, 95%CI: 1.14 to 1.31, p = 0.757). The certainty of the evidence for these outcomes was low to moderate.CQSDs seem to be effective therapy for SAP patients with notable reductions in mortality, MODS and abdominal pain, with low quality evidence. Large-scale, multi-center RCTs that are more meticulous are advised in order to produce superior evidence.Copyright © 2023 Elsevier GmbH. All rights reserved.