You can eat soda crackers or use medications such as domperidone, omeprazole, and ranitidine to treat the upset stomach and acid vomiting. Acid vomiting is mainly caused by excessive secretion of stomach acid. For patients with relatively mild symptoms, it can be improved by diet. Soda crackers contain a large amount of alkaline substances, and their intake can neutralize stomach acid, reduce the secretion of stomach acid, and alleviate the symptoms of acid vomiting. For patients with severe symptoms, medication should be considered. Domperidone can promote the recovery of gastric power, allowing the elimination of food in the stomach as soon as possible, shortening the time food stays in the stomach after meals, and reducing the secretion of gastric acid without the stimulation of food in the stomach. Omeprazole can inhibit the proton pump of the stomach wall, reduce the secretion of gastric acid, and prevent the stomach acid from causing irritation to the stomach wall. Ranitidine can also reduce the concentration of gastric acid, which can relieve the symptoms of stomach discomfort caused by excessive secretion of gastric acid.