Tooth decay in children is more common clinically, and in the fourth national epidemiological survey, it is found that the incidence rate of milk teeth in the group of 3-year-old children has reached 50%, and that in the age group of 5-year-old children has reached about 70.9%. The main reasons why children are prone to bad teeth include: 1, the main cause of tooth decay is oral bacteria, if children do not do effective brushing, there is a lot of plaque deposited on the tooth surface, which can easily lead to tooth decay; 2, there is a relationship with the anatomical structure of milk teeth, some children have deep sockets on the tooth surface, which can easily deposit some food residues, and there will be physiological gaps between some teeth, causing food embedding; 3, the teeth The mineralization degree of milk teeth is relatively lower than permanent teeth, so they are more sensitive to the resistance of acid produced by bacteria and easy to demineralize and cause tooth decay; 4, it is related to the diet structure of children, especially nowadays children especially like to eat sweets with high sugar content and sticky, and do not pay attention to oral hygiene, some children also like to sleep with milk or lollipop, which will easily lead to caries in children. Some parents don’t pay special attention to the caries of milk teeth and think that it doesn’t matter if the milk teeth are to be replaced, but in fact, when they finally visit the clinic, very serious caries will occur.