With the rapid improvement of techniques and equipment for cardiac surgery, extracorporeal circulation technology, anesthesia technology and post-operative monitoring, the success rate of ventricular septal defect repair surgery has been greatly improved. At present, the success rate of ventricular septal defect repair surgery in many domestic medical centers for precordial diseases is over 99%. Generally speaking, ventricular septal defect repair surgery has a good healing process and can be compared with normal children without any gap. However, there are some risks associated with ventricular septal defect repair surgery, and some complications may occur, even life-threatening. Since the heart function of children with ventricular septal defect is reduced to varying degrees compared to normal children, the surgery itself can be traumatic to the heart, and the extracorporeal circulation and general anesthesia can also have an impact on the heart function, so the recovery of heart function after ventricular septal defect repair surgery is a key issue for the success of the surgery. It is necessary to apply appropriate amount of cardiac drugs to help the early recovery of heart function after ventricular septal defect repair surgery, but if heart function cannot be recovered or even heart failure occurs after applying more cardiac drugs, it will be life-threatening. Surgical trauma can also lead to complications such as cardiac arrhythmias. Among them, complete atrioventricular block will have a greater impact on the heart function, and if it cannot be recovered, a pacemaker will be needed. In addition, extracorporeal circulation and the general process of anesthesia can also cause some damage to respiratory function, and children are prone to pulmonary complications such as pneumonia, atelectasis, pneumothorax, and pleural effusion after surgery, which can lead to respiratory failure and ventilator dependence in severe cases. In addition, because repair surgery involves a series of processes such as surgery, anesthesia, extracorporeal circulation, post-surgical monitoring and care, it may lead to endocarditis and sepsis in children with reduced resistance. Neurological complications are also possible after ventricular septal defect repair surgery, which may result in coma, convulsions, abnormal limb movements, loss of consciousness or vision, or even “vegetative state”. In short, parents must be well prepared before their children undergo ventricular septal defect repair surgery.