In our country, due to economic and technical reasons, many patients with congenital heart disease have delayed consultation, often combined with severe pulmonary hypertension, losing the best time for surgery, and whether they can benefit from surgery is the main issue in front of health care professionals. Pulmonary hypertension belongs to pulmonary hypertension. Pulmonary hypertension is the occurrence of hypertension in the intrapulmonary circulation, including pulmonary hypertension, pulmonary venous hypertension and mixed pulmonary hypertension. The entire pulmonary circulation, any systemic or localized lesion that causes increased blood pressure in the pulmonary circulation can be called pulmonary hypertension. Pulmonary hypertension is an isolated increase in pulmonary arterial blood pressure with normal pulmonary venous pressure. The main cause is an increase in pulmonary arterial resistance due to primary lesions of small pulmonary arteries or other primary diseases, which is manifested as an increase in pulmonary arterial pressure while pulmonary venous pressure is within the normal range. The diagnostic criteria for pulmonary hypertension are: systolic pulmonary artery pressure >30 mm Hg (1 mm Hg=0.133 kPa) and/or mean pulmonary artery pressure >25 mm Hg at sea level, at rest, on right heart catheterization, or mean pulmonary artery pressure >30 mm Hg during exercise. It should be emphasized that the strict diagnostic criteria should be based on right heart catheterization data and not on data estimated by noninvasive means (e.g., color ultrasound Doppler).