1.X-ray examination mainly shows that (1) because the main and pulmonary artery trunks are often arranged anteriorly and posteriorly, the orthopantomograph shows narrow shadow of the aorta, slightly depressed pulmonary artery, small heart tip and “egg-shaped” heart shadow. (2) Progressive enlargement of the heart shadow. The lung texture increases in most patients, but decreases in those with combined pulmonary artery stenosis. 2. The electrocardiogram may have no special changes in the neonatal period. In infancy, it shows right-sided electrical axis, right ventricular hypertrophy, and sometimes right atrial hypertrophy. When pulmonary blood flow increases significantly, the electrical axis may be normal or left-sided, and the right and left ventricles may be enlarged. In the case of combined atrioventricular access ventricular septal defect, the electrical axis is left deviated and both ventricles are hypertrophied.3. Echocardiography is a common method to diagnose complete transposition of the great arteries. If the two-dimensional ultrasound shows normal atrioventricular connections and inconsistent ventricular aortic connections, the diagnosis can be established. The aorta is often located anteriorly on the right and originates from the right ventricle, and the pulmonary artery is located posteriorly on the left and originates from the left ventricle. Color and Doppler ultrasonography can help to determine the direction and size of intracardiac shunts and to detect combined malformations.4. Cardiac catheterization can be inserted directly into the aorta from the right ventricle, and the right ventricular pressure is equal to that of the aorta. It may also be inserted into the pulmonary artery through the foramen ovale or atrial septal defect to the left heart cavity, and the oxygen saturation of the pulmonary artery is higher than that of the aorta. 5.Cardiovascular imaging selective right ventriculography can be seen in the aorta from the right ventricle, and left ventriculography can be seen in the pulmonary artery from the left ventricle. Selective ascending aortic angiography can show the position of the large arteries in relation to each other, and determine whether there is a combined coronary artery malformation.