Objective To explore the application and diagnostic value of 64-slice CT angiography (CTA) and ultrasonic cardiogram in the diagnosis of aortic dissection. Methods A total of 57 cases of aortic dissection diagnosed in our hospital from March 2015 to March 2018 were analyzed retrospectively. All patients were given 64-slice CTA and ultrasonic cardiogram to observe the abnormal diagnostic results of the two diagnostic methods (overall abnormalities, aortic arch abnormalities, aortic valve abnormalities, thoracic and abdominal aortic abnormalities, coronary artery abnormalities), DeBakey classification (type I, type II, type III) and Stanford classification (type A, type B). Results There were no significant differences in the overall abnormalities and aortic valve abnormalities between 64-slice CTA and ultrasonic cardiogram (P>0.05). The detection rate of abnormal aortic arch of ultrasonic cardiogram was higher than that of 64-slice CTA (P<0.05), and the detection rates of coronary artery abnormalities, thoracic and abdominal aortic abnormalities of 64-slice CTA were higher than those of ultrasonic cardiogram (P<0.05). There were no significant differences in the detection rates of DeBakey type I, DeBakey type II and Stanford type A between 64-slice CTA and ultrasonic cardiogram (P>0.05). The detection rates of DeBakey type III and Stanford type B of 64-slice CTA were higher than those of ultrasonic cardiogram (P<0.05). Conclusion There are certain defects in the clinical diagnosis of the two diagnostic methods, but the 64-slice CTA has obvious advantages than ultrasonic cardiogram, and it has relatively high clinical application value.