Esophageal cancer has become one of the common malignancies worldwide, and according to the global cancer statistics in 2020, the number of new cases of esophageal cancer reached 604,000 and the number of deaths reached 544,000. China is a region with high incidence of esophageal cancer. Although the incidence and mortality rate of esophageal cancer in China are decreasing, it is still the main malignant tumor threatening the health of Chinese residents. Precancerous disease refers to esophageal disorders that have some relationship with the formation of esophageal cancer and are independent diseases. The main ones are: chronic esophagitis, Barrett’s esophagitis, esophageal leukoplakia, esophageal diverticulum, cardia laxa, esophageal ductal type, reflux esophagitis and benign esophageal stricture. These precancerous diseases are more closely related to esophageal cancer. According to the literature, their cancer rates vary greatly, which may be related to the duration of the existence of precancerous disorders, the degree of esophageal emptying disorder and the irritated site, but more importantly, it is determined by the presence of concurrent pathological changes, including inflammation, ulceration, stricture, mucosal atrophy, mucosal leukoplakia, etc. Esophageal precancerous lesions are precancerous lesions characterized by heterogeneous squamous cells at different levels within the squamous epithelium of the esophageal mucosa. According to the level of lesion involvement, they are classified into low-grade intraepithelial neoplasia/heterogeneous hyperplasia (confined to the lower 1/2 of the squamous epithelium) and high-grade intraepithelial neoplasia/heterogeneous hyperplasia (involving more than the lower 1/2 of the squamous epithelium of the esophagus, previously called carcinoma in situ). For severe atypical hyperplasia and high-grade intraepithelial lesions, which are sometimes difficult to distinguish from carcinoma in situ of the esophagus, endoscopic mucosal debridement (ESD) is required to clarify the nature of the patient’s pathology and also to achieve a curative effect. For mild and moderate atypical hyperplasia, patients should undergo regular gastroscopy to observe the changes in both conditions. If some patients progress to severe atypical hyperplasia, early resection should be performed to prevent the development of carcinoma, which may cause more serious effects.