Aim To study the incidence rate and risk factors of postoperative delirium in patients with acute aortic dissection. Methods The perioperative clinical data of 173 patients with acute type A aortic dissection were retrospectively analyzed, including 151 males and 22 females, aged 45.4±10.3 years old. According to the appearance of postoperative delirium, patients were divided into delirium and non-delirium group, and the independent risk factors for postoperative delirium were analyzed. Results There were 72 cases with postoperative delirium in all of the patients, the incidence rate was 41.6%. Univariate and multivariate Logistic analysis showed that deep hypothermic circulatory arrest time (OR＝11.7,5%CI was 2.61～43.08), the lowest postoperative oxygenation index (OR＝2.6,5%CI was 1.43～5.72), duration of mechanical ventilation (OR＝4.2,5%CI was 1.36～15.59), hypernatremia (OR＝3.1,5%CI was 1.03～8.37), the amount of midazolam (OR＝1.8,5%CI was 1.07～2.04) were independent risk factors of postoperative delirium in patients with Stanford A aortic dissection. Conclusions The incident rate of postoperative delirium of Standford A aortic dissection patient is relatively high, deep hypothermic circulatory arrest time, the lowest postoperative oxygenation index, midazolam dosage, duration of mechanical ventilation and hypernatremia are independent risk factors of postoperative delirium in patients with aortic dissection.