The purpose of the treatment of milk tooth caries is as follows: 1, in the treatment, to interrupt the process of caries evolution, to prevent rotting to the nerve; 2, after the filling of milk teeth, not only to restore the aesthetic function, more importantly, to restore the chewing function, so that the teeth can chew correctly up and down, and to ensure the normal development of the face; 3, to prevent complications, if the tooth has rotted to the nerve, it can cause pulpitis or periapical inflammation, to stop this step properly. Children’s resistance is relatively weak compared to adults, if the tooth once rotten to the nerve, the pain will be more powerful than adults, and some affected children can not express well, which may lead to crying throughout the night or refuse to eat. Once the pulpitis develops further and becomes periapicalitis, it may lead to swelling of the whole face and jaw. Therefore, it is very important to fill the decayed milk teeth in time to prevent further development. If the milk tooth is not filled in time and the surface is decayed, a rotten root will be formed. The rotten root is not only unsightly, but the affected person will also develop low self-esteem, or lead to inaccurate pronunciation, and the whole person will not look confident or sunny.