With the eruption of permanent teeth in children, the rate of caries in permanent teeth is increasing, especially the earliest erupted six-year-old teeth, the rate of caries can reach up to 63%, therefore, it is very important to control the occurrence of caries in permanent teeth. Sixth-age teeth begin to erupt at about 6 years of age and remain there for the rest of life. Because of the earliest eruption of the six-year-old teeth, there are many grooves and cracks, which are easy to caries, and the position and relationship of the upper and lower jaw six-year-old teeth play an important role in establishing normal occlusal relationship, so it is necessary to retain and treat the six-year-old teeth. It is even more important to prevent caries before it occurs. Every year, we see many cases of caries in six-year-old teeth, which are very young, but the teeth are severely damaged, and some of them even cause irreparable loss, which greatly affects the function of chewing and other functions. Therefore, it is of great significance to have regular checkups of children’s teeth for early detection and treatment. Children can make use of the two annual holidays for regular oral examination to minimize the occurrence of caries or reduce the degree of destruction by caries. Treatment of six-year-old teeth should preserve the living pulp as much as possible, or if the pulp is already infected, the integrity of the tooth should be preserved as much as possible. To prevent caries, we should master the correct brushing method, rationalize the diet, and do regular oral examination. The occlusal and buccal surfaces of children’s milk molar and permanent molar teeth, which are prone to caries, can be closed with sealants, which can play a good role in preventing caries. Filling treatment can also be added at the same time fissure sealant. The application of fissure sealing can greatly reduce the occurrence of caries.