There are many reasons why six-year-old babies grind their teeth in bed at night, and they should be treated according to the causes, as follows: First, the common cause is poor oral hygiene, with dental caries, gingivitis or chronic pharyngitis. Usually we should develop the habit of brushing teeth in the morning and evening, rinsing mouth after meals, and actively treat infectious pharyngitis and other diseases. Second, some babies grinding teeth is related to poor digestive function, seen in the spleen, stomach function is weak, digestion, absorption poor baby. At this time, you can give your baby probiotics, regulate the gastrointestinal function, and take Chinese medicine to regulate the elimination of food and strengthen the spleen. Third, the baby may have upper digestive system diseases, such as acute and chronic gastritis, gastric ulcer, etc.. Usually it is important to note whether there is H. pylori infection, which requires standardized anti-H. pylori treatment. Fourth, a small number of babies may have intestinal parasitic infections, such as roundworms, pinworms and other infections caused, if there is a parasitic infection based on the need for deworming treatment.