Objective: To assess the predictive value of 24-hour lactate clearance rate (LCR) for postoperative mortality, multiple organ dysfunction syndrome (MODS), and other clinical outcomes in patients with severe abdominal blunt trauma undergoing emergency laparotomy. Methods: A retrospective cohort study was conducted on 348 patients with severe abdominal blunt trauma (American Association for the Surgery of Trauma [AAST] organ injury grade ≥ III) admitted to a Level 1 trauma center from January 2021 to December 2024. Venous lactate levels were measured on admission, and at 6, 12, and 24 hours postoperatively. LCR was calculated as [(admission lactate − 24-hour lactate)/admission lactate] × 100%. Patients were stratified by the optimal LCR cutoff value (≥25% vs. <25%) determined via receiver operating characteristic (ROC) curve analysis. Primary outcomes included 30-day postoperative mortality and MODS incidence within 7 days. Secondary outcomes encompassed intensive care unit (ICU) length of stay, total hospital stay, and unplanned reoperation rate. Results: The optimal LCR cutoff for predicting 30-day mortality was 25%, with an area under the curve (AUC) of 0.83, sensitivity of 85.1%, and specificity of 78.2%. Patients with LCR ≥25% had significantly lower 30-day mortality (6.7% vs. 35.2%, P<0.001) and MODS incidence (9.2% vs. 48.1%, P<0.001) compared to those with LCR <25%. Multivariate logistic regression confirmed LCR <25% as an independent risk factor for 30-day mortality (OR=5.89, 95% CI=3.21–10.83, P<0.001) and MODS (OR=6.72, 95% CI=3.68–12.26, P<0.001). Additionally, the LCR ≥25% group had shorter ICU stay (4.8 ± 1.5 days vs. 13.2 ± 3.8 days, P<0.001), shorter total hospital stay (13.6 ± 2.9 days vs. 28.1 ± 6.2 days, P<0.001), and lower unplanned reoperation rate (4.1% vs. 18.7%, P<0.001). Conclusion: The 24-hour lactate clearance rate is a reliable, cost-effective predictor of postoperative outcomes in patients with severe abdominal blunt trauma. An LCR <25% identifies patients at high risk of adverse outcomes, warranting intensified monitoring and targeted intervention.