Caries in both baby teeth and permanent teeth not only affects normal eating and malnutrition, but also affects the child’s pronunciation and appearance if not actively treated, and may even cause low self-esteem, affecting their physical and mental development. Having a mouthful of good teeth can be a lifelong benefit, so the prevention of dental caries is particularly important. According to the survey, the incidence of dental caries in our country is 80% -90%, the main reason is that now the children’s diet is more and more fine, eat less coarse grains, eat more sweets, originally not conducive to dental health, coupled with the age of too young, the surface of the teeth deep grooves, brushing is often not in place, it is very susceptible to erosion and caries. Prevention of caries in addition to the usual to monitor the child’s oral hygiene and dietary habits, fossa sealing is the World Health Organization (WHO) to the world’s children recommended one of the best methods of preventing tooth decay, it is the surface of the teeth, especially in the fossa of the teeth, coated with a layer of resin-based substances, forming a protective barrier to isolate the bacteria and acid on the teeth of the erosion, so as to prevent the occurrence of dental caries. Generally speaking, the best time for socket sealing is at the age of 3-4 years for milk molar, 6-7 years for six-year-old teeth, and 12-13 years for the second permanent molar.