With the increasing awareness of children’s oral health, the issue of fluoride application for children’s teeth is gradually attracting attention. After the baby’s teething to 14 years old belongs to the high risk period of tooth decay, regular fluoride application can prevent the occurrence of caries. At present, the commonly used fluoride in the market includes: fluoride toothpaste, fluoride mouthwash, fluoride gel, fluoride protective varnish, fluoride foam and so on. Depending on the fluoride coating material used, patients need to visit the dentist for regular follow-up every 3 months or every 6 months. However, excessive fluoride intake can lead to dental fluorosis, fluorosis and other dangers. The results of a systematic review study in the United States showed that children who swallowed pea-sized or larger amounts of fluoride toothpaste when brushing with fluoride toothpaste can lead to mild dental fluorosis. In children aged 2 to 3 years weighing s10 to 15 kg, for example, swallowing more than ^50 to 75 g may lead to fluorosis (about one strip of toothpaste in a small package and about half a strip in a large package). Household fluoride mouthwash (0.05%) a can of about 300 ~ 500cc, each use about 5 ~ 10cc, weight about 10kg, if swallowed by mistake more than 215cc may be poisoned (about 1/2 ~ 2/3 can). Therefore, children’s teeth fluoride application must be done by a professional dentist in a regular dental institution, and the time, frequency and concentration of fluoride application should be strictly controlled. It is not recommended to apply fluoride to children under 3 years old because they are too young to cooperate well with the doctor’s operation and may lead to fluoride accidental ingestion.