Atrial septal defect is one of the common types of congenital heart disease, with an incidence of 1/1000 of live births, and is often a combined malformation of many complex congenital heart diseases. The symptoms of simple atrial septal defect in pediatric period are mostly mild, and many children are not discovered until they become adults, and it is more common in females. 1, medical treatment: children with heart failure early after birth should first be given furosemide, digoxin and captopril and other anti-heart failure treatment, and maintain adequate nutritional supply to stabilize the condition to reach the appropriate age for surgical treatment. Long-term medication is not advisable to delay surgery, but surgery should be considered if medication does not relieve the condition. Preoperative oxygenation can reduce or minimize the occurrence of postoperative pulmonary hypertension crisis. 2.Surgical treatment: Except for very few patients with small septal defect and no atrioventricular valve regurgitation, almost all patients with atrioventricular septal defect need to receive surgical treatment. Pulmonary hypertension and pulmonary vascular disease occur early in children with complete atrioventricular septal defect, so surgery is recommended at about 6 months of age. In recent years, there has been a trend toward earlier surgery to 3 to 4 months of age. Surgery should still be performed early if drug control of heart failure is ineffective. If the operation time is too long, large fractional flow and severe atrioventricular regurgitation will make the ventricle and annulus expand and aggravate atrioventricular regurgitation, and the valve at the regurgitation will undergo fibrotic changes, and pulmonary hypertension will also increase. The risk of surgery after the age of 4 years is relatively low in the presence of other cardiac malformations such as tetralogy of Fallot, double right ventricular outlet, or ventricular dysplasia. Simple partial atrial septal defects can be treated surgically at the age of 12 years.