Esophageal cancer is a malignant tumor originating from the mucosal epithelium of the esophagus, which is one of the common malignant tumors in clinical practice. China is a country with high incidence of esophageal cancer, with more than 220,000 new cases of esophageal cancer and about 200,000 deaths each year. Early-stage esophageal cancer can usually be cured by minimally invasive endoscopic treatment, and the 5-year survival rate is over 95%, while the 5-year survival rate is less than 20% for progressive (middle and late stage) esophageal cancer. Early detection, early diagnosis and early treatment are the main strategies to reduce mortality and increase survival rate. Electronic endoscopy and pathological biopsy are the most important methods to detect early esophageal cancer. Screening targets: According to the national conditions and epidemiological characteristics of esophageal cancer in China, those who meet any one of Article 1 and 2-6 should be listed as the high-risk group of esophageal cancer and are recommended to be the screening targets: 1. over 40 years old, 2. from high esophageal incidence area; 3. with upper gastrointestinal symptoms; 4. with family history of esophageal cancer; 5. with pre-cancerous diseases or pre-cancerous lesions of esophagus; 6. with other high-risk factors of esophageal cancer ( smoking, heavy alcohol consumption, squamous carcinoma of the head and neck or whistle tract, etc.).