Objective To investigate the association between albumin-corrected anion gap（ACAG） and short- to long-term death outcomes in patients with acute pancreatitis（AP）. Methods This retrospective study was based on the Medical Information Mart for Intensive Care-IV database，and the adult patients who were diagnosed with AP and were admitted to the intensive care unit were enrolled in this study. Cox regression risk analysis，receiver operating characteristic（ROC） curve analysis，Kaplan-Meier survival curve analysis，restricted cubic spline，and subgroup analysis were used to investigate the value of ACAG in predicting the death outcome of AP patients. Results A total of 444 patients were enrolled in this study，and according to the death status of the patients on day 28 after admission，the patients were divided into survival group with 412 patients and death group with 32 patients，with a mortality rate of 7.2% on day 28 after admission. The multivariate Cox regression analysis showed that ACAG was an independent predictive factor for all-cause mortality rate on day 28 after admission in AP patients（hazard ratio［HR］=1.18，95%CI=1.05-1.32），while it was not an independent predictive factor for death outcome on days 90（HR=1.05，95%CI=0.97-1.14） and 180（HR=1.01，95%CI=0.94-1.09） and at 1 year（HR=1.02，95%CI=0.95-1.10）. The ROC curve analysis showed that ACAG had an area under the ROC curve（AUC） of 0.732（95%CI=0.632-0.832） in predicting 28-day death outcome，which was better than that of AG（AUC=0.665，95%CI=0.550-0.781） and serum albumin（Alb）（AUC=0.655，95%CI=0.550-0.761） and was similar to that of Sequential Organ Failure Assessment（SOFA） score（AUC=0.745，95%CI=0.651-0.838）. The ROC curve showed that the optimal cut-off value of ACAG was 21.375. Based on the cut-off value of ACAG of 21.375，the patients were divided into high-value group and normal-value group，and the Kaplan-Meier curve analysis showed that the patients with a high level of ACAG had a significantly higher mortality rate than those with normal ACAG（P<0.001）. The subgroup analysis showed that the results were stable. Conclusion ACAG can be used as an independent predictive factor for all-cause mortality rate on day 28 after admission in AP patients，with a better efficacy than AG and Alb and a similar efficacy to SOFA. However，it is not significantly associated with 90-day，180-day，and 1-year death outcomes in AP patients.