Abstract Background Acute coronary syndrome (ACS) has become a major public health problem worldwide due to its high morbidity and mortality. In addition to traditional risk factors, psychosocial factors play an important role in the development of ACS.Type D personality, as a combination of social inhibition and negative affect, has been defined as a psychological risk factor for coronary heart disease by the European Society of Cardiology.Meanwhile, ACS patients with Type D personality may have behaviors such as unhealthy dietary behaviors, less regular physical activity, and poorer self-management behaviors. Then, whether the combination of Type D personality and poor cardiovascular health behaviors can increase the risk of poor prognosis in patients with ACS requires further research. Purpose The aim of this study was to investigate the effect of Type D personality combined with poor cardiovascular health behaviors on long-term major adverse cardiovascular events(MACE) in patients with ACS. Methods A total of 18631 patients diagnosed with ACS between January 2017 and July 2023 were included in this study. Type D personality, cardiovascular health behaviors (smoking cessation, physical activity, average sleep duration at night, dietary assessment index, BMI, lipids, blood glucose, blood pressure) were assessed during the admission period, and were divided into poor, general, and ideal cardiovascular health with a cut-off score of 50 and 80.The binary logistic regression analysis was used to assese the effect of Type D personality combined with cardiovascular health score on the occurrence of MACE (stroke, reinfarction, revascularization, all-cause death). Results The median follow-up in this study was 37 months, and we found that a total of 3750 people had MACE during the follow-up period. The logistic regression result showed that compared with Type D personality (-) and cardiovascular health behaviors (poor) group, Type D personality (+) and cardiovascular health behaviors (poor) group (OR=1.451, 95%CI=1.055-1.995,P=0.022), Type D personality (+) and cardiovascular health behaviors (general) group (OR=1.425, 95%CI=1.092-1.858,P=0.009), Type D personality (-) cardiovascular health behavior (poor) group (OR=1.301, 95%CI=1.013-1.670, P=0.039) were independent risk factors for the occurrence of further adverse cardiovascular events. Conclusion Type D personality combined with unhealthy cardiovascular behavior individuals may be at high risk for MACE. Therefore, early assessment of Type D personality and cardiovascular health behaviors are needed, thereby reducing the incidence of MACE in ACS patients.