The eustachian tube is a tube that connects the nasopharynx to the middle ear cavity, and its role is mainly to regulate the air pressure in the middle ear and keep it in balance with the outside world. The eustachian tube is often dysfunctional due to mechanical blockage. The most common cause in pediatrics is adenoid hypertrophy. The adenoids, also known as the accretion bodies or pharyngeal tonsils, grow on the posterior wall of the nasopharyngeal apex and are often hyperplastic due to recurrent respiratory infections. Overly enlarged adenoids can compress the pharyngeal orifice of the eustachian tube and impair the function of the eustachian tube in regulating air pressure in the middle ear. Rhinitis and sinusitis in pediatric patients are also important causes of mechanical blockage of the eustachian tube, and active treatment of sinusitis can effectively improve the function of the eustachian tube. The maintenance of eustachian tube function also depends on the function of the muscles that affect the normal opening and closing of the eustachian tube, i.e., the palatal sail tensor and palatal sail lift muscles. In children with combined cleft palate, the two muscles are prone to dysfunction because they are split at the midline. Eustachian tube dysfunction can be complicated by otitis media and a series of complications, so when we find a cause that can affect the function of the eustachian tube, we must actively treat it and not ignore it.