The surgical steps of thoracoscopic atrial septal defect repair mainly have three stages: preoperative preparation, thoracoscopic stage, and after completion of repair. 1. Preoperative preparation: after general anesthesia, tracheal intubation, femoral vein intubation, etc. are performed and extracorporeal circulation is established. 2. Thoracoscopic stage: 3 holes were made in the right chest wall of the patient to facilitate the septal repair under thoracoscopy. Three small incisions were made in the chest wall, namely the 4th intercostal space on the right side of the sternum, the 3rd intercostal space on the right axillary midline, and the 7th intercostal space on the right axillary midline. After finding the right phrenic nerve under thoracoscopy, the pericardium was incised above the right phrenic nerve, and after the upper and lower vena cava were blocked by ligation, the atrial septal defect was repaired by direct suture repair or patch method. 3. After the repair is completed: after the repair of the atrial septal defect is completed, the right atrial incision is sutured. The patient’s upper and lower vena cava were reopened, rewarmed, extracorporeal circulation was stopped, each cannula was removed, and the three holes in the chest wall were adequately hemostatized. Depending on the patient’s condition, the surgical procedures used may vary, and patients are advised to consult a specialized physician at a regular hospital.