Esophageal cancer is a malignant tumor occurring in the epithelial tissue of esophagus, accounting for 2% of all malignant tumors. China is a high incidence area of esophageal cancer, with the incidence age mostly above 40 years old and more men than women. The occurrence of esophageal cancer is related to the chronic stimulation of nitrosamines, inflammation and trauma, genetic factors and the content of trace elements in drinking water, food and vegetables. Diagnostic methods of esophageal cancer: (1) X-ray barium meal examination: It is one of the important means to diagnose esophageal and cardia tumors, which can provide reliable information for studying early esophageal cancer, and combined with cytology and esophageal endoscopy, it can improve the accuracy of esophageal cancer diagnosis. Barium meal X-ray examination of esophageal cancer not only needs to determine the location, length and obstruction degree of lesions, but also needs to determine whether there is external invasion of esophageal lesions and the extent of external invasion. (2) CT examination: CT scan can clearly show the relationship between esophagus and adjacent mediastinal organs, but it is difficult to detect early esophageal cancer. Combining CT and X-ray examination can help improve the diagnosis and staging of esophageal cancer. 2.Gastroscopy: Fiber optic gastroscopy has been widely used in the diagnosis of esophageal cancer. Esophagoscopy can directly observe the size, shape and location of tumor to provide clinicians with the basis for treatment, and also can be used for biopsy or mirror brush examination at the lesion site. Esophagoscopy combined with exfoliative cytology examination is an ideal diagnosis method for esophageal cancer.