Spitting up is a very common digestive symptom in infants and toddlers, and in most cases it is a physiological phenomenon, except for digestive disorders and gastrointestinal obstruction. In addition, external environmental changes and unclean diet can also lead to vomiting. Infants have immature organs and an imperfect digestive system, so too much milk feeding or improper feeding posture can lead to vomiting, which generally does not require special treatment. On the other hand, digestive system dysfunction plays an important role in the cause of vomiting in infants and children may also have symptoms such as thinness, fatigue and lack of weight gain, which require symptomatic treatment such as adjusting the feeding situation and regulating the intestinal flora. Gastrointestinal obstruction can also be seen clinically, commonly including pyloric obstruction and stenosis, intestinal obstruction, etc., which requires further examination and treatment at the hospital and, if necessary, surgery. Some infectious diseases can also cause vomiting, usually accompanied by fever, rash, abdominal pain and diarrhea, which require routine blood and stool tests and anti-infection treatment if necessary. In short, there are many reasons for vomiting, and the causes need to be identified and treated symptomatically. Parents should promptly clean up after infants and toddlers who spit up to prevent aspiration pneumonia from occurring.