Congenital heart disease is an unfortunate event for both the child and the family, but it is a blessing in disguise if there is an opportunity for surgical correction. I often talk to parents of children with congenital heart disease about preoperative anesthesia, so I will write about it today so that more parents can have sufficient time to understand it before surgery. Pre-operative surgery requires general anesthesia, and no matter how complex the subsequent operation, all that is needed initially is a small, drug-administering vein. After intravenous administration of anesthetic, analgesic and inotropic drugs, the child falls asleep and is under general anesthesia. Depending on the age of the child, a tracheal tube is inserted and a ventilator is connected to give mechanical ventilation. Because of the complexity of cardiac surgery and the many factors affecting it, the following operations are also performed to create the conditions for the cardiac surgeon: (1) arterial puncture for monitoring the blood pressure after each beat of the heart, which is more accurate and timely than the usual blood pressure measured through a cuff, so that even an occasional decrease in blood pressure due to a premature beat can be clearly displayed on the monitor; (2) central venous puncture for the purpose of (2) central venous puncture for monitoring central venous pressure and thus for identifying hypotension due to blood volume or cardiac function, and also for continuous infusion of catecholamines, especially in children with tetralogy of Fallot; (3) femoral venous puncture for providing access to supplemental blood volume. After completing the above operations, it is time for the surgeon to sterilize the procedure. Throughout the procedure, anesthesia can be maintained by inhalation of anesthetic gas or by continuous intravenous infusion of drugs. After the surgeon has completed the main steps of the surgery and the extracorporeal circulation is ended, the anesthesiologist will continue to use cardiovascular active drugs and other drugs to maintain the child’s vital signs stable. In addition, anesthesiologists also need to use organ-protective drugs, hemostatic drugs and other drugs during surgery, so anesthesiologists are also acting as “internal medicine doctors” in the operating room at this time. Regardless of the type of surgery, the anesthesia procedure is basically similar, but the anesthesiologist needs to use different drugs and anesthesia management according to the child’s condition in order to cooperate with the cardiac surgeon and ultimately achieve satisfactory surgical results.