Objective：This study sought to develop and validate a nomogram incorporating clinical factors and complete blood count (CBC)-derived inflammatory indices, designed to predict all-cause mortality in diabetic patients following their first acute myocardial infarction and primary percutaneous coronary intervention(pPCI).  Methods: This retrospective multicenter cohort study analyzed patients with concomitant diabetes and myocardial infarction who underwent pPCI, collected from 82 hospitals between 2010 and 2024. Patients were categorized into survival and non-survival groups. Restricted cubic spline (RCS) analysis was employed to examine the relationships between SII, SIRI, AISI, NLPR and mortality. The nomogram was constructed by integrating independent predictors identified through multivariable Cox regression, with the optimal model selected based on minimal AIC value. Subjects were stratified into high- and low-risk groups according to the median nomogram score. The model's performance, clinical utility, and validity were assessed using the C-index, calibration curves, decision curve analysis (DCA), and survival curves. Results: A total of 3403 eligible patients were included with 1-year all-cause mortality of 4.06%.RCS curves revealed significant non-linear relationships between SII,SIRI,AISI,NLPR and 1-year mortality (P-nonlinear < 0.001). Multivariable Cox regression analysis identified 10 independent predictors for 1-year mortality after adjustment, including SII and SIRI. These predictors were incorporated into a nomogram model optimized by minimal AIC value. The model demonstrated excellent discriminative ability (C-index: 0.895) and good calibration (Hosmer-Lemeshow test: 0.6092). Decision curve analysis confirmed clinical utility with net benefit thresholds ranging from 0.01 to 0.78. Patients stratified into high-risk groups based on the median nomogram score showed significantly elevated mortality compared to low-risk groups. Conclusion:Some biomarkers such as SII and SIRI were identified as independent predictors of 1-year mortality after pPCI in patients with diabetes and first myocardial infarction. An economical and robust nomogram integrating these novel inflammatory markers with conventional risk factors was developed and validated in Tianjin, China, and demonstrated satisfactory performance.