ESD surgery is called endoscopic submucosal dissection in Chinese, which is a standard minimally invasive treatment for precancerous lesions and early cancers of the gastrointestinal tract, with the features of less trauma, more complete pathological specimens taken by surgery, more thorough treatment and less recurrence rate, allowing more early gastrointestinal cancers to be completely removed under endoscopy in one go, eliminating the pain of open surgery and removal of organs. Surgery is performed to peel off the lesion under endoscopy, and it is mainly applied to the following diseases: 1. early stage cancer: if it is determined that the tumor is confined to the mucosal layer and the submucosal layer without lymphatic metastasis, ESD resection of the tumor can achieve the same therapeutic effect as surgery; 2. huge flat polyps: polyps over 2 cm, especially flat polyps, can be treated with ESD to completely remove the lesion at one time; 3. submucosal tumors. Lipomas, mesenchymal tumors and carcinoid tumors diagnosed by ultrasonic endoscopy can be completely stripped by ESD if the location is shallow; if the tumor is deeper, ESD stripping of the lesion is often accompanied by the occurrence of gastrointestinal perforation, but forced stripping is not advocated, and doctors with rich experience in endoscopic treatment can try to apply it. After surgery, patients need to routinely fast from food and water and observe for 24-48 hours. If patients do not have vomiting blood, black stool, abdominal pain, subcutaneous emphysema, etc., they can enter liquid diet. If abnormalities occur during this process, the fasting time should be extended and a gastric tube can be placed for gastrointestinal decompression if necessary.