Vomiting in the middle of the night in a two-year-old child may be caused by indigestion, acute gastroenteritis, gastrointestinal cold and other factors. 1. Indigestion: consuming a lot of greasy and cold food before going to bed at night may lead to indigestion, which may easily cause vomiting in the middle of the night, and may be accompanied by nausea, abdominal distension and other symptoms. 2. Acute gastroenteritis: consuming unclean food may trigger acute gastroenteritis, which may cause children to vomit in the middle of the night, accompanied by diarrhea, abdominal pain, fever and other symptoms. 3. Gastrointestinal colds: usually caused by viral infections, which can cause children to develop digestive tract-related symptoms, such as vomiting, nausea, abdominal pain, abdominal distension, and so on, but also can only be manifested in the form of vomiting. There may be other reasons for a two-year-old child to vomit in the middle of the night, and it is recommended to go to the hospital in time, complete the examination to clarify the cause of the disease, and then give targeted treatment or treatment.