Caries is a common disease in children’s oral cavity, if not treated in time, it is very easy to affect the dental pulp, and cause pulpitis, or periapical inflammation, and affect the growth and development of permanent teeth and milk teeth, and even affect the growth and development of jaw bone, and may also cause the digestive function to be reduced, and the nutrition disorder leads to the slow growth and development …… soon after the milk teeth are erupted, they can suffer from caries. The calcification degree of the milk teeth is low, the acid resistance is poor, the teeth and the adjacent surface are easy to retain bacteria and food debris, and the children’s food is mainly liquid food, semi-liquid food, and sugar food is mostly, so it is easy to adhere to the teeth, the sugar in the food, under the action of bacteria, acid production, so that the calcified part of the teeth decalcify, and lead to caries. In general, it is difficult for children to maintain oral hygiene consciously, some children eat sweets such as candy and cookies before going to bed, and even sleep with sugar, plus children sleep for a long time, the time of the mouth in a static state is also long, the secretion of saliva is reduced, the role of sweating is lowered, which provides favorable conditions for bacteria and reproduction, so that the occurrence of caries is greatly increased. How to effectively prevent and control children caries? We should start from the etiology, combine with the developmental characteristics of children and diet, hygiene habits, etc., and make a comprehensive analysis. Specific methods are summarized as follows: I. Keep oral hygiene: brush teeth every morning and evening, rinse mouth after meal, and master the correct brushing method, it is appropriate to adopt. Second, fluoride caries prevention using fluoride toothpaste, or using fluoride medication coating in the hospital. Third, sulcus closure: for narrow and deep sulcus, using sulcus sealant can effectively prevent the occurrence of sulcus caries. The timing of sealant for milk molar is appropriate at the age of 3-4 years old. Limit the intake of sugar: eat less sugar, avoid eating sugar between meals (the rate of caries is higher if you eat sugar between meals), do not eat sweet food before going to bed, and wash your mouth after eating sugar or sweet food. V. Diet to prevent caries: eat more fibrous food, supplement protein, vitamin A, D, calcium and phosphorus in appropriate amount, which can improve the anti-caries ability of teeth and prevent the occurrence of caries. Actively treat the caries that has occurred. Regular check-up: Take children to the stomatology department of general hospital for check-up regularly. In a word, parents should pay attention to cultivate children’s oral hygiene habits, from the eruption of milk teeth, they should use clean wet gauze to clean their teeth surface. Parents should check and supervise children’s teeth regularly, and treat the caries in time once it is found.