Thick yellow tongue and bad breath may be caused by high mental stress, prolonged late nights, irregular work and rest, or frequent consumption of spicy and irritating foods, smoking, and failure to take good care of oral hygiene in a timely manner. It may also be due to gastrointestinal dysfunction and a thick yellow tongue, which may cause bad breath. It is recommended to use mouthwash to regulate the flora environment in the mouth, such as compound chlorhexidine gargle, boric acid solution, rehabilitation new liquid or compound thick tinidazole, and can use open throat sword spray, stomatitis spray, watermelon cream spray, etc. It is also recommended to maintain good oral hygiene, regular checkups and scaling, scraping when necessary, and should brush the tongue in time when brushing teeth. If there is gastrointestinal disorder should be treated timely related diseases, and it is recommended not to eat food with heavy taste.