Why do people get esophageal cancer? The exact cause of esophageal cancer is still unclear, but it is largely related to several aspects: first, nitrosamines and fungal toxins, the first point, nitrosamines, nitrosamines are recognized as chemical carcinogens, and their content is significantly higher in food and drinking water in areas with high incidence of esophageal cancer, and is positively correlated with the local prevalence of esophageal cancer and esophageal epithelial hyperplasia. The second point, the carcinogenic effect of fungal toxins, various moldy foods can produce carcinogenic substances, such as Fusarium, Aspergillus and Aspergillus niger and other fungi, which can not only reduce nitrate to nitrite, but also increase the content of secondary amines and promote the synthesis of amyl nitrite; the second aspect, dietary stimulation and chronic esophageal stimulation. It is generally believed that chronic physical and chemical stimulation of esophageal mucosa caused by rough food and overly hot food can lead to limited or diffuse epithelial hyperplasia, forming precancerous lesions of esophageal cancer; thirdly, nutritional factors, lack of animal protein, fresh vegetables and fruits in the diet and lack of vitamin intake are risk factors of esophageal cancer; fourthly, genetic factors, the development of esophageal cancer often shows the phenomenon of family gathering; fifthly, oncogenes, environmental and genetic factors. The occurrence of esophageal cancer caused by multiple factors such as environment and genetics involves molecular biological basis, which is currently considered to be caused by activation of oncogene or inactivation of oncogene; sixth, human papillomavirus, some studies found that esophageal epithelial hyperplasia is related to papillomavirus infection, while esophageal epithelial hyperplasia is related to esophageal cancer, but the exact relationship between them needs further study.