Endoscopic surgery technology is an important part of modern minimally invasive technology, its characteristics are: the endoscope through the body’s natural external channels or artificially established channels to the human body lesions, under the direct vision of the endoscope or combined with X-ray fluoroscopy or ultrasound-mediated use of endoscopic surgical instruments for hemostasis and removal (stones and stones foreign bodies) drainage and cavity organ channel reconstruction, in order to achieve a clear diagnosis to relieve the symptoms of the purpose of curing the disease. Endoscopy can be divided into: gastroscopy colonoscopy pancreaticoduodenoscopy small intestine microscopy whole gastrointestinal capsule endoscopy biliary tract microscopy fiber tracheobronchoscopy ultrasound endoscopy and so on according to its use. According to the nature of light transmission is divided into: fiberoptic endoscopy and electronic endoscopy. The significant advantage of endoscopic surgery technology is that it is easier, faster, safer, less painful and less complications than traditional open surgery and laparoscopic surgery, and the total cost is relatively low. At present, the endoscopic techniques that are relatively mature are: injection: mainly used for hemostasis to promote tumor necrosis and local closure of small perforations. Clamping: to prevent bleeding and actually stop bleeding to close the wound. Excision: excision of the lesion after direct or dissection of the mucosa on the surface of the lesion. Guidewire catheter placement: The front end of the guidewire is aligned with the stenosis under direct vision, and the stenosis is passed by “twisting” the guidewire based on finger resistance sensation or with the aid of X-ray fluoroscopic surveillance, and then a drainage catheter is placed through the guidance of the guidewire to achieve the treatment purpose. Dilatation: The stenotic segment of the internal organ is gradually dilated with a probe dilator or balloon dilator under direct endoscopic or x-ray vision under the guidance of a guidewire to relieve the stenosis or reconstruct the channel. Stenting: Plastic or metal stents are placed in the cavernous organ with stenosis under endoscopic or combined x-ray surveillance alone to maintain patency. Drainage: endoscopic puncture of a fluid cystic cavity or drainage of body fluid through the upper segment of a cavernous organ in the presence of a stenosis obstruction to the body’s internal cavity or outside the body. Lithotripsy: endoscopic lithotripsy and lithotripsy and lithotripsy treatment with special equipment such as mechanical lithotripter hydrodynamic lithotripter laser lithotripter ballistic lithotripter ultrasound lithotripter. Argon knife coagulation: endoscopic coagulation of the target object (tumor stenosis, bleeding point, foreign body, etc.) with an APC probe to cause coagulation and necrosis and vaporization. Ultrasonic endoscopic puncture: endoscopic puncture needle is used to determine the target object for puncture under the guidance of ultrasonic endoscopy in order to achieve needle aspiration for pathological examination, injection of medicine and Yang treatment or establishment of a channel for treatment purpose. Duodenal papillotomy: the use of endoscopic papillotomy knife to open the access to the pancreatic duct or bile duct. The earliest endoscopic surgical techniques used in clinical practice are duodenal papillotomy, which was developed in gastrointestinal endoscopic surgery, and the built-in esophageal tube, which is an endoesophageal injection hemostasis, and bile duct drainage, which have become the classic basic techniques of endoscopic surgery and have been developed and innovated based on them. A gastrointestinal endoscopic surgical techniques of clinical applications: 1, the application of gastrointestinal tract disease treatment: endoscopic hemostasis of gastrointestinal bleeding: gastrointestinal bleeding is divided into variceal bleeding and non-variceal bleeding, the latter is divided into limited bleeding and diffuse bleeding, endoscopic hemostasis in gastrointestinal bleeding is widely used: including portal hypertension caused by ruptured esophagus – gastric fundus variceal bleeding, esophagus – cardia mucosa bleeding, bleeding from esophagogastroduodenal ulcers, bleeding from gastrointestinal polyps and tumors, and bleeding from ruptured vascular malformations. However, large arterial bleeding, arteriovenous-gastrointestinal fistula bleeding, bleeding with large perforation and extensive exudative bleeding are relative contraindications to endoscopic hemostasis, which is said to be relatively contraindicated because with the continuous development and improvement of technology and the introduction of new instruments, endoscopic hemostasis for these difficult hemorrhages is gradually being tried and carried out in clinical practice. The main methods of hemostasis for variceal bleeding are ① injection sclerotherapy ② embolization hemostasis ③ ligation hemostasis. The main methods of hemostasis for non-variceal venous bleeding are injection electrocoagulation microwave laser argon knife thermal probe and hemostatic clips alone; they can also be used in combination. Among them, the injection method hemostasis clip combined with hemostasis method is most commonly used and effective, argon knife coagulation cut method (APC) is most effective for malignant tumor bleeding. 2.Treatment of gastrointestinal malignant tumors: For in situ carcinoma of the mucosa and submucosa of the gastrointestinal tract (especially esophagogastric and colorectal) less than 2 cm, without muscle layer infiltration and distant lymph node metastasis (preoperative CTMRⅠ and ultrasonic endoscopic confirmation), endoscopic mucosal resection (EMR) can be used to remove the cancer foci, and for the remaining small foci, argon knife coagulation can be used to eliminate them. For patients with advanced malignant tumors that cannot be radically resected, endoscopic hemostatic luminal recanalization can be used to relieve symptoms, improve the patient’s psychological status and enhance the quality of life. The endoscopic luminal recanalization techniques mainly include ① tumor injection sclerosing necrolysis and thermal coagulation necrolysis ② stenosis dilatation ③ stent tube placement in the stenosis lumen. 3.Treatment of benign stenosis of the gastrointestinal tract Endoscopic treatment of benign stenosis of the gastrointestinal tract can effectively relieve the symptoms and partially cure them, and the main techniques are ① stenosis dilatation ② cautery combined with dilatation ③ stent placement. 4.Treatment of gastrointestinal polyps and benign tumors Endoscopic resection is mainly adopted for some of these diseases ①Polyp removal: including hot biopsy forceps clamping coagulation removal trap ring removal or combined use. For large polyps or flat polyps larger than 4.0 cm in diameter, multi-block resection can be performed ②Papillary duodenal adenoma resection, which can be performed after selective pancreatic duct and bile duct internal drainage, and removed after one week to prevent postoperative pancreatitis and cholangitis ③Submucosal tumor resection: direct trap removal or peel off the tumor after mucosal incision. 5. Treatment of GI perforation and fistula This part mainly includes the palliative treatment of esophageal-tracheal fistula caused by malignant tumor, which is a pathological perforation of the colorectum or anastomotic leak after colorectal surgery, mainly by endoscopic placement of a laminated stent tube to block the perforation and fistula, improve symptoms and cure benign diseases. Endoscopic percutaneous gastrostomy/jejunostomy Compared with surgical stoma, endoscopic stoma is more simple, fast and effective with low complications, easy to accept and care for patients with less pain, and can be replaced in situ several times, and endoscopic surgical treatment of hepatobiliary and pancreatic diseases. Endoscopic retrograde cholangiopancreatography (ERCP) was the first to be performed for diagnostic imaging of this part of the disease. Currently, this simple diagnostic technique has a tendency to be replaced by magnetic cholangiography (MRCP), but the technology developed on the basis of ERCP technology for therapeutic purposes is gradually developing into one of the important tools for the treatment of hepatobiliary and pancreatic diseases. It mainly includes ① transnasal pancreaticobiliary drainage ② duodenal papillotomy ③ percutaneous transhepatic choledochoscopic technique (PTCS). 1.Treatment of extrahepatic bile duct stones: ①Duodenal papillotomy for stone extraction ②Lithotripsy ③Drainage. 2.Treatment of intrahepatic bile duct stones: EHL (microscopic liquid electro-lithotripsy)-lithotripsy under PTCS. 3.Treatment of bile duct obstruction, leakage and inflammation: ① external bile drainage ② internal bile drainage. 4.Treatment of pancreatitis: for acute pancreatitis, perform duodenal papillotomy under pancreaticoduodenoscopy to remove embedded stones and perform pancreaticobiliary duct decompression drainage. For chronic pancreatitis pseudopancreatic cysts, pancreatic duct dilatation pancreatic ductoplasty pancreatic duct lithotomy transgastric pancreatic pseudocyst built-in duct drainage can be performed.