Compared with conventional surgery, minimally invasive occlusion has the advantages of no extracorporeal circulation, simple operation, less trauma, less pain, no blood transfusion, no placement of chest drains, less possibility of air embolism, beautiful incision, fast recovery, and short hospital stay. Compared with interventional occlusion techniques, the advantages of minimally invasive occlusion of atrial septal defect are as follows: ①The occluder is orthogonal to the septal defect opening, which is more direct and easy to operate. ②The placement is safer and more reliable. The operator finally tests the firmness of the closure by pushing and pulling it vertically, which makes it less likely to fall off and have residual leakage after surgery. ③The indications are wider. ④If placement fails, the occluder can be retrieved, and then the incision can be lengthened and remedied with a right-sided extracorporeal circulation procedure. ⑤The cost is less than the interventional method.