Due to the current crowd diet irregularities lead to gastrointestinal dysfunction, affecting the digestion and absorption of food in the gastrointestinal tract, resulting in food residues stagnant in the stomach through the mouth and nose to form a sour and corrosive flavor. Common causes of sour mouth after meals are: First, oral disease is one of the most common diseases. The oral cavity is rich in a large number of anaerobic bacteria, through the decomposition of food residues to produce a large amount of hydrogen sulfide, this material will emit a sour and rotten taste; Second, adolescent women often appear after meals, mouth acidic taste, which is related to physiological functions. Adolescent women’s ovarian development is not perfect, oral antimicrobial capacity is reduced, the oral cavity is susceptible to bacterial infection and produce a large number of acidic substances; Third, smoking, drinking alcohol, drinking coffee, eating onions, leeks and other foods easily lead to sour taste in the mouth.