Digestive tract tumors are highly prevalent in China, and their mortality rate ranks first among malignant tumors. Among digestive tract tumors, esophageal cancer, stomach cancer and colorectal cancer are the most common. Early detection, early diagnosis and early treatment of digestive tract tumors are of great significance to individuals, families and the society. Early stage digestive tract tumors have a survival rate of more than 90% after treatment, while late stage tumors have a survival rate of only about 30% in 5 years. So, how to find digestive tract tumors in early stage? What methods can treat early tumors and improve the quality of life and survival of tumor patients? At present, gastrointestinal endoscopy (gastroscopy, enteroscopy) is the preferred method of digestive tract examination. At present, the most advanced gastroscopy and enteroscopy equipments in China can not only complete ordinary endoscopy, but also have the functions of magnification and staining, together with the stains such as Lugol’s solution and indigo carmine, which are very accurate for the discovery and diagnosis of early tumors. And also painless endoscopy technology can be used, anesthesiologists make it possible for patients to complete the whole endoscopy process in their sleep, completely painless. Most of the patients with digestive tract tumors do not have any symptoms in the early stage, and almost all of them are in the middle or late stage after the symptoms appear, thus physical examination, especially checking gastroenteroscopy for high-risk groups, is particularly important. Generally speaking, middle-aged people over 50 years old with family history of tumor; chronic gastritis, moderate atypical hyperplasia, gastric bleeding, intestinal bleeding in the previous gastroscopy; polyps in the stomach and colon, mucus stool, blood stool, etc. need to pay attention to gastroenteroscopy. In areas with high incidence of gastrointestinal tumors, gastroenteroscopy should be performed routinely for early detection and treatment of early gastrointestinal tumors. When early tumors or high risk precancerous lesions are detected, surgical treatment was required in the past, while endoscopic minimally invasive surgery is now available in many cases. These early tumors are screened out those without metastasis and limited to the mucosa, and then according to the size, shape, location, nature and depth of invasion of the lesion, endoscopic mucosal resection (EMR), segmental mucosal resection (EPMR), submucosal dissection (ESD), etc., can be used to remove the tumor completely, and can be combined with the application of argon ion coagulation therapy, thermal probe, etc., to destroy the diseased tissue , to achieve the purpose of eliminating the tumor. The trauma should be closed with metal clips, ligatures and medical glue, which is equivalent to the role of suture or anastomosis in surgery. Postoperative patients need to pay attention to adhere to strict follow-up.