The cricoid cartilage, located in the epiglottis, is the only intact cricoid cartilage of the larynx and trachea, and plays an important role in supporting the respiratory tract and maintaining its patency. The cricoid cartilage corresponds to the level of the sixth cervical vertebra, and the lower edge of the cricoid cartilage is an important landmark in physiological anatomy: its plane not only corresponds to the plane of the six cervical vertebrae, but also is the location of the first physiological stenosis of the esophagus, which corresponds to the interface between the larynx and the trachea, the vertebral artery penetrating into the foramen transversarium of the sixth cervical vertebra, and the location of the laryngeal reentrant nerve entering the larynx.