The international association for thestudy of pain (IASP) defines pain as an unpleasant subjective sensory and emotional experience associated with actual or potential tissue damage. Pain is already considered the fifth most important vital sign indicator. Neurobiological studies have shown that infants and children have a 3- to 5-fold stronger endocrine response to painful stimuli after surgery than adults. The postoperative stress response in children with congenital heart disease (CHD) is more intense because of the use of cardiac arrest and the assistance of extracorporeal circulation. In order to reduce postoperative pain and postoperative stress and complications, it is necessary to provide postoperative analgesia for children with congenital heart disease. Therefore, continuous analgesic sedation is routinely administered to children in our hospital CICU, and good results have been achieved.