Gastroscopy and colonoscopy are required for health check-ups. Research shows that it takes more than ten years or even decades to develop from precancerous lesions to cancer. If early stage cancer and precancerous lesions are detected and diagnosed in time during this period, they can be treated and cured with minimally invasive endoscopic treatment. Authoritative data show that the five-year survival rate after endoscopic resection for early-stage esophageal cancer is over 90%, while the five-year survival rate after surgery for advanced esophageal cancer is less than 25%, which shows the importance of early detection. However, due to the influence of traditional concept and fear of gastroscopy and colonoscopy, many patients often go to hospital only when they have obvious symptoms such as difficulty in swallowing, vomiting blood, abdominal pain or difficulty in defecation and blood in stool, which leads to the discovery of most patients with middle and late stage cancer, with poor efficacy and high cost, and the best time for early cure is lost. At present, using advanced endoscopic equipment, early detection, diagnosis and treatment of early cancer and precancerous lesions, and interrupting the occurrence and development of cancer have become the best measures to reduce cancer mortality and improve survival rate.