The timing of surgical treatment for children with precardiac disease depends on the type of disease and its severity. Theoretically, children with precocious heart disease older than 2 years of age will have organic changes in their pulmonary vascular bed and should be operated before. The principle is to operate as early as possible in the early years to improve the systemic blood supply and oxygenation, and to correct the secondary anatomic lesions surgically before they become aggravated. Children with mild symptoms and lesions that do not affect growth and development (e.g., small atrial septal defects and small ventricular septal defects) may not be operated because of the possibility of natural healing (generally healing within 2 years of age and less likely to heal after 5 years of age), but they should be followed up every six months to a year for review to grasp the changes in pulmonary artery pressure and the healing of the defect and to determine whether to operate and the timing of surgery. For some patients with obvious symptoms (such as recurrent respiratory infections, pneumonia, cardiac insufficiency) and serious lesions (such as complete pulmonary venous ectopic drainage, atrial septal defect, large ventricular septal defect, large patent ductus arteriosus, or children with compound malformations), surgery should be performed in a timely manner; children with tetralogy of Fallot need to be operated within 2 years of age (preferably within one year of age) for radical treatment, as long-term ischemia and hypoxia will affect the development of other organs, aggravate secondary malformations, and affect the development of other organs. In children with severe cyanosis, such as transposition of the great arteries and pulmonary atresia, surgery should be performed immediately in the neonatal period; in certain neonates with severe hypoxemia, acid-base imbalance and progressive deterioration, or with recurrent respiratory infections, respiratory failure, heart failure, and difficulty with medical treatment, surgery should be performed as soon as possible. In some severe malformations of precardiac disease, surgery should be performed in stages, with palliative surgery in infancy, followed by second-stage radical surgery according to the condition; if most precardiac diseases are not treated, the heart malformations and secondary lesions will become more and more complex and severe. Early detection, early diagnosis and early treatment are the keys.