A small hole in the ear with a foul odor is usually seen as a congenital preauricular fistula with infection. Congenital preauricular fistula is a congenital malformation of the ear caused by underdevelopment, malformation or fusion of the first and second gill arches during fetal development, often with a small hole at the ear screen, which can be asymptomatic when there is no infection, but once the ear screen is infected with water and inflammation, the skin at the ear screen can become swollen and painful, and in severe cases, abscesses can appear, and squeezing can cause purulent secretions to ooze out with a foul odor. In terms of treatment, first of all, symptomatic and anti-inflammatory treatment is needed, oral anti-inflammatory drugs, cefixime and amoxicillin can be taken orally, and local wiping with iodophor and alcohol repeatedly. If the abscess once formed, it needs to be incised and drained to drain the abscess, preferably when the patient is not infected, surgery is needed to remove the blind end of the fistula fistula together, so that it can be completely eradicated and avoid recurrence.