Small children are affected by certain diseases that cause them to be noticeably thin compared to normal children. Obviously thin children is one of the clinical symptoms of congenital heart disease. Infants and young children with congenital heart disease are significantly behind the development of children of the same age, manifested by thinness, malnutrition and developmental delay. Congenital cardiovascular disease is the most common type of congenital malformation. With the progress of cardiac diagnostic methods and surgical treatment techniques, the vast majority of congenital cardiovascular disease can now obtain a clear diagnosis and surgical correction treatment, and the prognosis is significantly improved compared with the previous. Pediatric obviously thin preventive methods: 1, do a good job of pregnancy health care Although the etiology of congenital heart disease is not yet very clear, but in order to prevent the occurrence of congenital heart disease, attention should be paid to the mother’s pregnancy, especially in the early stages of pregnancy health care, such as actively preventing rubella, influenza, mumps and other viral infections (infection refers to the invasion of pathogens such as bacteria, viruses, fungi, parasites and so on into the human body caused by the local tissues and the systemic inflammatory reaction). Avoid exposure to radiation and some harmful substances. Use medication under doctor’s guidance and avoid taking drugs that will have an effect on the development of the fetus, such as anticancer drugs, methylglycine, and so on. Actively treat the primary disease, such as diabetes mellitus. Pay attention to reasonable diet and avoid nutritional deficiency. Prevent localized mechanical compression around the fetus. In short, in order to prevent congenital heart disease, we should avoid all factors related to the onset of the disease. 2, avoid strong magnetic fields in early pregnancy (3 months before) try not to sit too long in front of the computer microwave ovens and other strong magnetic fields, because this time the fetus is still unstable organs are still in the process of forming stage is likely to cause congenital heart disease in children. 3, avoid contact with pets do not contact with pets because the pet body bacteria and microorganisms may also cause congenital heart disease in children. 4, marriage examination congenital heart disease in children the incidence rate of about 4 ‰ ~ 8 ‰, can be said to be a common congenital diseases. With the improvement of medical level, many children with congenital heart disease after surgery, life and normal people. However, all people who have had congenital heart disease want to have a healthy child when they become parents themselves, and the best way to do this is to go to the hospital for premarital testing and genetic counseling before marriage.