It is not normal for a 3-year-old child to vomit twice at night, which can be caused by irrational diet, cold abdomen and gastrointestinal inflammation. 1. Irrational diet: eating too much dinner, eating cold food, too greasy food, etc., will lead to the child vomiting at night. 2. Cold abdomen: When sleeping at night, the temperature is too low, the abdomen is easy to get cold, and vomiting will occur, it is recommended to do a good job of keeping warm. 3. gastrointestinal inflammation: unhygienic diet can lead to gastrointestinal inflammation, nausea and vomiting, abdominal pain and diarrhea and other manifestations. The 3-year-old child vomited twice at night may also have other reasons, it is recommended to go to the hospital, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.