Vomiting in 3-year-old children can be seen in gastrointestinal disorders, neurological disorders, metabolic-related diseases and other conditions, treatment needs to be based on the cause, such as intracranial occupations need to be evaluated by a physician, and if necessary, surgical treatment. 1. Gastrointestinal dysfunction: such as improper diet or sudden change of weather and other factors, can affect the gastrointestinal function, vomiting symptoms, such children should pay attention to a reasonable diet, discretionary increase or decrease in clothing, if necessary, need to be taken orally to help digestion, Lactobacillus acidophilus to regulate the intestinal flora treatment. 2. Neurological diseases: such as intracranial space occupation, may appear cranial hypertension manifestations, such as projectile vomiting, improve the cranial CT examination can assist in the diagnosis, such children need to be evaluated by specialists, if necessary, surgical treatment. 3. Metabolism-related diseases: such as diabetic ketoacidosis, gastrointestinal symptoms, such as vomiting, depression, blood glucose can be seen to be significantly elevated, metabolic acidosis, urine ketone bodies can be seen positive. This kind of children need intravenous rehydration to correct dehydration, acidosis and electrolyte disorders, if necessary, to take a small dose of insulin intravenous drip and other treatments. 4. Other: such as trauma, caused by intracranial hemorrhage, may also appear the above symptoms, such children need to use vitamin K, phenol sulfonyl ethylamine, etc. to control bleeding, and if necessary, need to carry out surgical treatment. The above medications should be used under the supervision of a physician. It is recommended that children aged 3 years who are vomiting actively consult a specialist for evaluation of the cause of vomiting and guidance for treatment.