Tooth decay in children should be treated with fillings, root canals and extractions depending on the severity. 1. If the tooth is simply decayed with no other complications, it can be filled with glass ionomer or resin material after removing the decay to achieve the treatment purpose. 2. If the tooth also has pulpitis or periapical inflammation, it is necessary to remove the decayed area with an electric drill in time for root canal treatment to reduce pain and protect the crown. 3. When the decayed tooth affects the permanent tooth to be inherited, the decayed tooth needs to be extracted and a retainer should be used to leave a space for the permanent tooth to grow. Therefore, you should practice good oral hygiene, brush your teeth on time, eat less sweets and carbonated beverages, and have regular dental checkups to prevent the emergence and development of tooth decay.