The child, female, 9 months old, 5 kg, was significantly less developed than young children of the same age and had a poor diet. On examination, there was no cyanosis of the lips, no jugular vein anger, no obvious elevation in the precordial region, heart rate of 125 beats/min, regular rhythm, systolic murmur of grade I/6 could be heard in L2, P2 was obviously hyperactive, and femoral artery gunshot sound (±). The echocardiogram showed that the main pulmonary artery was 21 mm, the ascending aorta was 9 mm, the diameter of the unclosed ductus arteriosus was 5.5 mm, a left-to-right shunt bundle could be detected through the unclosed ductus, the maximum cross-ductal pressure difference was 5 mm Hg, and the estimated mean pulmonary artery pressure was 54 mm Hg. The diagnosis was “congenital heart disease, unclosed ductus arteriosus, pulmonary hypertension (severe) “. Oxygen saturation at the toe end was 84% with calm without oxygen and 95% with oxygen (0.5L/min). After admission, oxygen and prostilbestrol were given, and the necessary preparation was followed by occlusion of the unclosed arterial catheter under general anesthesia. The intraoperative angiogram showed that the diameter of the unclosed ductus arteriosus was 5 mm and the diameter of the descending aortic arch was 8.5 mm, and the pressure measurement was 101/53 (70) mm Hg in the descending aorta and 91/44 (65) mm Hg in the main pulmonary artery. A 6 mm VSD blocker was used. The blocker was successfully blocked at one time, and the pressure was measured: no differential pressure from ascending to descending aorta, 79/40(58)mmHg in the main pulmonary artery, and the angiogram showed satisfactory position and morphology of the blocker, and no residual shunt. The blocker was released. After the operation, the child continued to receive oxygen, prostilbestrol and sildenafil, etc. He was clear, in good spirits, eating well and resting well at night. The echocardiogram on the 7th day after surgery showed that the blocker was satisfactorily positioned, there was no residual shunt, and the estimated pulmonary artery systolic pressure was 45 mm Hg. The child was discharged from the hospital.