CT examination is commonly used in the diagnosis of pediatric diseases, for three-year-old baby perfect CT there is a certain radiation, but the harm is small, it is recommended to follow the doctor’s advice to perfect. CT examination is a commonly used means of examination in pediatrics, which is of great significance for the diagnosis of certain diseases, such as cranial CT can assist in the diagnosis of intracranial hemorrhage, intracranial space occupation, etc., and thoracic CT has diagnostic significance in the diagnosis of tracheal foreign bodies. CT examination is usually non-invasive, high accuracy, for this age group of babies, although there is a certain degree of radioactivity, but it is believed that the side effects are small, safer, such as the condition of the need to improve the CT examination to assist in the diagnosis of the disease, it is usually believed that the advantages outweigh the disadvantages, and it is recommended to improve the disease, to avoid delays in the diagnosis of the disease and treatment, and the occurrence of adverse consequences. It is recommended to actively seek medical attention and consult a specialist.