Barret’s esophagus is not a specific anatomical location of the esophagus, but a pathological phenomenon in which the compound squamous epithelium of the lower esophagus is replaced by a single layer of columnar epithelium. The site of columnar epithelium that replaces the squamous epithelium is called Barret’s epithelium, and the site of Barret’s epithelium may become malignant and develop esophageal adenocarcinoma. Barret’s esophagus may have no specific symptoms, but it has recurrent gastroesophageal reflux for many years. The symptoms include acid reflux, heartburn, epigastric distention, belching and regurgitation. In combination with esophageal adenocarcinoma, dysphagia and bleeding may occur. A part of Barrett’s esophagus may be a congenital ectopic development of the esophageal epithelium. However, it is more commonly seen as a result of long-term chronic gastroesophageal reflux injury. Some studies have shown that if the inflammation of the esophageal mucosa remains uncontrolled for a long time, it increases the progression of Barrett’s esophagus. This means that the mucosa of the lower esophagus can be irritated by chronic acid reflux, resulting in the replacement of the compound squamous epithelium of the esophageal mucosa by a single layer of columnar epithelium. Therefore, patients with Barret’s esophagus often have clinical symptoms of reflux esophagitis, such as retrosternal pain, acid reflux, painful swallowing or difficulty swallowing. Barret’s esophagus needs to be diagnosed by gastroscopy or esophagoscopy with pathological examination, and attention needs to be paid to whether there are any changes in the morphology of the dentate line and the occurrence of ulcers and whether they are accompanied by strictures. Once the diagnosis is confirmed, several treatments are needed with the cooperation of the doctor, such as lifestyle modification, combined application of drugs, and if other complications occur, such as heterogeneous hyperplasia of the Barrett’s epithelium and suspected tumor, treatment can be performed under gastroscopy, or surgery is needed if the cancer progresses. Barrett’s esophagus is a lesion of the esophageal epithelium, and gastroesophageal reflux is the main cause of Barrett’s esophagus.