Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart and vascular disease in older children, including pulmonary artery stenosis, ventricular septal defect, right aorta (riding over the defective ventricular septum), and right ventricular hypertrophy. The main ones are ventricular septal defect and pulmonary artery stenosis. The symptoms of tetralogy of Fallot can appear after birth or within a few weeks, manifested as cyanosis, and gradually worsen. The first three items are primary lesions and are of great significance; while right ventricular hypertrophy is a secondary change, which is the consequence of the above-mentioned deformities. Echocardiography has very specific manifestations of this disease and can be used as a basis for the diagnosis of this disease.