Atrial septal defects of 1.5 mm generally do not require treatment, due to the fact that 1.5 mm atrial septal defects have a greater likelihood of healing on their own, and regular clinical observation as well as regular cardiac ultrasound observation of the size of the atrial defect defect is sufficient. Atrial septum is divided into three categories according to the diameter of the defect: In young children, 3-6mm is a small defect, 6-12mm is a medium defect, and more than 12mm is a large defect; in adults, less than 10mm is a small defect; between 10-20mm is a medium defect; and more than 20mm is a large defect. Patients with small defects can be treated without surgery, while patients with medium or large defects that are combined with significant symptoms are recommended to undergo surgery. Depending on the type of atrial septal defect, the appropriate treatment plan can be chosen. For patients with central atrial septal defect, interventional occlusion can be performed, while other types of atrial septal defects, including supratentorial, infratentorial, or mixed, can be selected for surgical procedures, including direct suture, patch repair, and so on. Patients with atrial septal defects are recommended to undergo early and standardized treatment to reduce the adverse effects of the disease.