The symptoms of vomiting after drinking milk may be related to the lack of lactase in the body. If the lactose in milk is not completely decomposed and digested, it may lead to the fermentation and growth of a large number of bacteria in the intestinal tract, producing too much gas, which may also lead to an increase in stomach acid, nausea and vomiting. If you have gastritis or gastric ulcer, drinking milk on an empty stomach may lead to vomiting symptoms. If the symptoms of vomiting after drinking milk are accompanied by diarrhea, abdominal pain, bloating and other symptoms, it may be related to gastroenteritis or indigestion, you can take drugs such as patchouli, lactase, and eat more millet porridge and other foods that nourish the stomach to improve, or you can go to the gastroenterology department for examination and treatment for the cause.