Gill slit fistulas cannot usually be detected by ultrasound. A gill slit fistula is a gill-like fissure that appears in the neck of an embryonic baby and opens to the right and left; this fissure is a gill slit that does not close completely as the embryo develops, and can result in a gill slit fistula when there are openings at both ends, such as in the ear canal or throat. Gill slit fistula is a congenital genetic condition. It is not easily detected by ultrasound during pregnancy and is usually only found in children or adults. Surgery to remove the fistula is considered when the patient develops localized redness, swelling and pain or even purulent discharge oozing from the area. The use of cephalosporin antibiotics such as cefuroxime before surgery to control the infection in a timely manner facilitates the surgical operation and reduces the chance of intraoperative bleeding and postoperative infection. Patients with gill slit fistula should go to the hospital for timely examination and surgical treatment under the guidance of the doctor. After surgery, pay attention to oral hygiene, rinse the mouth after meals to reduce the contamination of food residues.