When toothache occurs in the decayed teeth of five-year-old children, the following treatment measures can be taken: 1.When a deep cavity is produced in the milk tooth and the pulp cavity is squeezed by the embedded chunks of food, a sharp digging spoon can be used to remove the residue of retained food, and after disinfection with alcohol, calcium hydroxide can be placed at the bottom of the cavity and filled with composite resin, etc. 2.If the pulp is exposed in the cavity and pulpitis or periapical inflammation occurs, the cavity can be removed under local anesthesia, and the root canal can be filled with calcium oxide paste after disinfection and the cavity repaired. If the infected pulp is removed and the root canal is disinfected, calcium oxide paste is applied to fill the root canal and repair the cavity. 3.If the milk tooth forms residual root and crown, causing repeated infection of gum or loose tooth, the prognosis is poor, a gap retainer can be made after extraction and wait for the eruption and replacement of permanent tooth.