Atrial septal defect is a relatively common congenital heart disease in pediatrics, and is more common in girls, accounting for about 20% of congenital cardiac visceral disease. The causes are as follows: 1. In the first trimester of the mother’s pregnancy, some genetic factors of the mother, together with unfavorable environmental factors, cause abnormalities in the development of the child’s atrial septum; environmental factors are viral infections are the most common, such as coxsackie virus, adenovirus, influenza virus, echovirus, mumps virus, etc., which can cause abnormal fetal heart development; 2. The mother takes anti-cancer drugs, anti-epileptic drugs, and some mothers have diabetes or folic acid deficiency, all of which can cause defects in the development of the atrial septum during the embryonic development of the child, and after birth, the left and right atria are connected because of the gap left in the atrial septum. It is easy to cause heart failure in children; children repeatedly get pneumonia, and because of the lack of blood supply in the body, children’s growth and development become slow, pale, etc. Therefore, clinically, it is necessary to choose the appropriate surgery opportunity or interventional surgery according to the size of the child’s defect.