The clinical manifestation of dental fluorosis is characterized by chalky to brownish plaques on the enamel that erupted during the same period, and in severe cases, it is complicated by parenchymal defects in the enamel. Clinically, it is often divided into three types according to its light, medium and seriousness: chalky (mild), stained (medium) and defective (serious). 1, the clinical manifestation of dental fluorosis is characterized by chalky to brownish plaques on the enamel erupted in the same period, and the serious ones are also complicated by the enamel’s parenchymal defects. Clinically, it is often divided into three types of chalky (mild), stained (moderate) and defective (severe) according to its light, medium and severe degrees. 2, mostly seen in permanent teeth, occurring in the milk teeth is rare, the degree is also mild. This is due to the occurrence of milk teeth in the embryonic period and milk infancy, and the placenta has a certain barrier effect on fluoride. Therefore, dental fluorosis is generally seen in permanent teeth, but if the fluoride intake is too much, more than the limit of its screening function, it can also be irregularly manifested on the milk teeth. 3.Poor tolerance to abrasion, but strong resistance to acid erosion. 4, severe chronic fluorosis patients, there can be proliferative changes in the bones, periosteum, ligaments, etc. can be calcified, and thus produce lumbar, leg and general joint symptoms. Acute poisoning symptoms are nausea, vomiting, diarrhea and so on. As blood calcium combines with fluorine to form insoluble calcium fluoride, it causes muscle cramps, collapse and respiratory difficulties, resulting in death.