Objective To investigate the diagnostic value of prenatal ultrasound diagnosis of fetal right aortic arch, in order to improve prenatal diagnosis rate. Method Retrospectively summarize the information and follow-up results of 33 cases of right aortic arch fetal diagnosed with prenatal ultrasound in our hospital,and compared with the date of postpartum echocardiography or autopsy results after induction, the sonographic features were also analyzed. Results Among 33 cases of right aortic arch fetal diagnosed with prenatal ultrasound, 19 cases of simple right aortic arch, 10 cases associated with other cardiac malformations, 4 cases with cardiac abnormalities, all patients showed the abnormal three-vessel trachea view image and follow-up results confirmed the existence of a right aortic arch. Conclusion prenatal ultrasound diagnosis of right aortic arch shows clear diagnostic value, Three-vessel trachea view is an important aspect of ultrasound diagnosis of fetal right aortic arch with characteristic features, should pay attention to when scanning line blood vessels, to avoid misdiagnosis.