Objective: To investigate the predictive value of lactate clearance rate (LCR) within 24 hours after surgery for postoperative outcomes in patients with severe abdominal blunt trauma. Methods: A retrospective cohort study was conducted on 312 patients with severe abdominal blunt trauma (American Association for the Surgery of Trauma [AAST] organ injury grade ≥ III) who underwent emergency laparotomy between January 2020 and December 2023. Venous blood lactate levels were measured on admission, at 6, 12, and 24 hours postoperatively. LCR was calculated using the formula: [(admission lactate - 24-hour postoperative lactate)/admission lactate] × 100%. Patients were stratified into two groups based on an optimal LCR cutoff value (≥30% vs. <30%) identified by receiver operating characteristic (ROC) curve analysis. The primary outcome measures were 30-day postoperative mortality, incidence of multiple organ dysfunction syndrome (MODS), and length of intensive care unit (ICU) stay. Secondary outcomes included postoperative complication rate, total hospital stay, and rate of reoperation. Results: The optimal LCR cutoff value for predicting 30-day mortality was 30%, with a sensitivity of 82.3% and specificity of 76.5%. Patients with LCR ≥ 30% had significantly lower 30-day mortality (7.2% vs. 31.8%, P<0.001) and MODS incidence (10.5% vs. 42.7%, P<0.001) compared to those with LCR < 30%. Multivariate logistic regression analysis confirmed that LCR < 30% was an independent risk factor for 30-day mortality (OR=5.21, 95% CI=2.87–9.45, P<0.001) and MODS (OR=6.12, 95% CI=3.38–11.11, P<0.001). Additionally, the LCR ≥ 30% group had shorter ICU stay (5.2 ± 1.8 days vs. 12.6 ± 3.5 days, P<0.001) and total hospital stay (14.5 ± 3.2 days vs. 26.8 ± 5.7 days, P<0.001), as well as lower postoperative complication rate (18.3% vs. 53.6%, P<0.001) and reoperation rate (4.8% vs. 17.5%, P<0.001). Conclusion: Lactate clearance rate within 24 hours after surgery is a reliable and easy-to-obtain predictor of postoperative outcomes in patients with severe abdominal blunt trauma. An LCR < 30% indicates a high risk of adverse outcomes, and close monitoring and aggressive intervention should be implemented for these patients.