Stenosis at the outlet of the pulmonary artery, resulting in obstruction of right ventricular drainage, includes pulmonary valve stenosis, right ventricular funnel stenosis and stenosis of the suprapulmonary valve, main pulmonary artery and branches, which is more common in precordial disease and has a similar incidence in males and females. In mild to moderate stenosis, systolic jet sounds can be heard in the pulmonary valve region. The disease causes great damage to the patient’s body, so we also need to do early preventive measures to avoid this disease. Pulmonary valve area can be heard in the jet sound prevention: 1, maintain an optimistic and happy mood. Long-term mental tension, anxiety, irritability, pessimism and other emotions, will make the balance of cortical excitation and inhibition process is out of balance, so you need to maintain a happy mood. 2, ask the family history to understand the genetic situation, investigate the influence of environmental factors, in order to explore the etiology of congenital heart disease. 3.Surveillance of maternal diseases and fetal malformations can be performed on the mother and fetus before and during pregnancy. 4.Obstetrical checkups should be conducted during pregnancy to diagnose whether the fetus is suffering from hereditary diseases and congenital defects in time. 5, the child should eat less and more meals, need to ensure adequate protein and vitamin intake, give the diet as diverse as possible, easy to digest. 6, to keep the stool can be smooth, if the stool is dry, defecation difficulties, excessive force will increase abdominal pressure, increasing the burden on the heart, and may even have serious consequences. 7, indoor air circulation, children try to avoid staying in crowded public places to reduce the chance of respiratory infections. The child should add or remove clothes in time with the cold weather and pay close attention to the prevention of colds.