The Eustachian tube is a duct structure that connects the nasopharynx and the middle ear cavity. When the Eustachian tube loses its resting closure function and remains continuously open for various reasons, it is called a patulous Eustachian tube (PET). PET is a common otolaryngological disorder and its typical symptoms include autophony, hearing one's own breathing sounds, subjective tinnitus, and ear pressure. PET patients’ symptoms are similar to those of ETD, which can easily be missed or misdiagnosed. This article presents a review of the latest research progress on the diagnosis and treatment of PET. Regarding diagnosis, symptoms, signs, and laboratory tests are essential for PET diagnosis, but there is no single Eustachian tube function test that can accurately evaluate ET function without other clinical observations and examinations. In terms of treatment, common methods include conservative treatment and surgical treatment. For PET patients, a "stepwise" treatment strategy can be employed, such as weight gain, nasal irrigation, and acid drops as conservative treatments; if the conservative treatment is ineffective, the symptoms are severe and the patient expresses a strong need for treatment, then invasive surgical treatments like tympanic membrane surgery, plug surgery, or tuboplasty can be performed.