The causes of teeth grinding in children’s sleep at night are related to the incongruity of occlusal relationship, abnormal awakening from sleep, mental and psychological disorders, and the presence of systemic diseases. Teeth grinding is a relatively common clinical oral disease, mainly manifested as intermittent isotonic contraction of jaw muscles, and is accompanied by regular chewing movements, commonly found in children. Children’s teeth grinding in bed at night is mostly related to uncoordinated occlusal relationship. In addition, the child is too excited during the day, mental tension and other reasons, will lead to the brain in a state of localized excitation, causing abnormal contraction of the chewing muscles, the occurrence of teeth grinding. In addition, if the body has intestinal parasitic infection, endocrine disorders, gastrointestinal dysfunction, rickets, hyperthyroidism and other systemic diseases, it is also a common cause of teeth grinding. There may be other reasons for children to grind their teeth at night, it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, and then give targeted treatment or treatment.