An odontogenic cutaneous fistula is a way for inflammation of the tooth to drain pus through the skin. Odontogenic cutaneous fistula is the emergence of apical inflammation is not timely treatment. In the early stages of dental caries, bacterial infection of the nerve causes pus and necrosis of the pulp tissue, and early inflammation is confined to the root of the tooth. If not effectively treated, the inflammation will gather in the apical area and further break through the alveolar bone to drain pus outward through the skin, forming a cutaneous fistula. The fistula appears on the surface of the skin and will remain there if the tooth is not treated. Odontogenic cutaneous fistula is triggered by dental caries, and the phenomenon of skin drainage of pus that occurs when the necrosis of the nerve of the tooth is not treated in time, i.e., it leads to periapical inflammation, which needs to be treated in time, and needs to be treated in the stomatology department.