Objective To explore independent risk factors for aspiration pneumonia (AP) in ICU patients receiving mechanical ventilation (MV), develop and validate a nomogram prediction model. Methods A retrospective analysis was conducted on 300 ICU patients undergoing MV at Haian People's Hospital Affiliated to Nantong University from April 2020 to March 2025. The patients were divided into a AP group (n=71) and a Non-AP (n=229) groups based on AP occurrence during treatment. Independent risk factors were identified using multivariate logistic regression. A nomogram prediction model was constructed using R3.5.1, and model performance was evaluated using receiver operating characteristic (ROC) curves and calibration plots. Results Among 300 ICU-MV patients, 71 (23.7%) cases developed AP. Univariate analysis showed that AP patients had significantly higher proportions of advanced age, impaired consciousness, intermittent cuff pressure monitoring, elevated intra-abdominal pressure, poor oral hygiene, and prolonged MV duration, while subglottic secretion drainage was less frequent (P<0.05). Multivariate analysis confirmed these as independent AP risk factors: advanced age (OR=1.047, 95%CI 1.004-1.093), impaired consciousness (OR=1.468, 95%CI 1.148-1.877), intermittent cuff pressure monitoring (OR=2.496, 95%CI 1.300-4.790), elevated intra-abdominal pressure (OR=1.313, 95%CI 1.027-1.678), poor oral hygiene (OR=1.640, 95%CI 1.244-2.161), and prolonged MV duration (OR=1.233, 95%CI 1.116-1.363) (all P<0.05). The final prediction model was logit(P)= –11.242 + 0.046×Age + 0.384×Consciousness + 0.915×Cuff Pressure Monitoring + 0.272 × Intra-abdominal Pressure + 0.495×Oral Hygiene + 0.209×MV Duration. Hosmer-Lemeshow test indicated good fit (χ2=4.136, DF=8, P=0.825). A nomogram-derived risk score>250 predicted>85% AP probability. Model validation showed a C-index of 0.802, AUC of 0.802 (95%CI 0.752-0.845), sensitivity of 79.01%, specificity of 88.17%, cutoff value of 0.287, Youden's index of 0.672, Brier score of 0.117, and calibration slope of 0.613. Conclusions Advanced age, impaired consciousness, intermittent cuff pressure monitoring, intra-abdominal hypertension, poor oral hygiene, and prolonged MV duration significantly increase AP risk in ICU-MV patients. The developed nomogram demonstrates robust predictive accuracy and clinical applicability.