Duodenoscopic papillotomy (EST) is an endoscopic treatment technique developed on the basis of the diagnostic technique of duodenoscopic retrograde cholangiopancreatography (ERCP), which is mostly applied to the treatment of bile duct stones and accounts for more than 80% of the indications. With the increasing maturity of ERCP clinical application, the development of therapeutic ERCP has been accelerated. It has many advantages: (1) It does not require general anesthesia, especially for the elderly and those who have contraindications to surgery. (2) No abdomen opening, less trauma and less pain. (3) Short treatment time (20-30 minutes to complete) and short hospital stay (3-5 days). (4) Safe and less complications. Compared with traditional surgical procedures, therapeutic ERCP is superior in many aspects such as hospitalization time, safety and repeatability. It opens up a new treatment route for those who do not want to undergo open surgery and those who are contraindicated to surgery, and can replace part of the conventional surgical treatment, and even part of the emergency surgical procedures. The prevalence of gallbladder stones combined with common bile duct stones has been clinically documented to be about 11%-20%. In recent years, laparoscopic cholecystectomy (LC) has become the procedure of choice and is accepted by most patients. For common bile duct stones, they are managed by therapeutic ERCP with minimal invasiveness. In patients with gallbladder stones combined with common bile duct stones, therapeutic ERCP creates surgical conditions for LC, and the combination of the two scopes has the characteristics of rapid postoperative recovery and relative economy. Our gastrointestinal endoscopy unit has carried out ERCP technology since 1984 and accumulated rich clinical experience, carrying out therapeutic ERCP programs including EST, bile duct lithotripsy for stone extraction, biliopancreatic duct internal stent (metal, plastic) drainage, biliopancreatic external drainage (nasobiliary duct, nasopancreatic duct), biliopancreatic duct stricture dilatation and many other techniques, treating thousands of cases of bile duct stones (including about 2.5cm (including huge stones of about 2.5cm) with a success rate of over 99%. After years of practice, we have learned the advantages of therapeutic ERCP: (1) it is widely used and can overcome the disadvantage of bile duct injury after common bile duct exploration, and can avoid reopening of the residual bile duct stones after LC treatment of gallbladder stones; (2) it can repeat the treatment of bile duct stones; (3) it has fewer complications, and the incidence of ERCP and EST complications is 5.1% to 10.0% as reported in the literature. Our treatment is less than that reported in the literature, and the main complications are mild pancreatitis and cholangitis, and there are no fatal cases; ④ ERCP can clearly diagnose patients who cannot be clearly diagnosed by MRCP; ⑤ emergency therapeutic ERCP can make stone removal and bile drainage smooth, which is effective in acute septic obstructive cholecystitis. Biliary flushing through nasal bile duct drainage (ENBD) can also be performed to provide rapid relief. (6) ERCP and ENBD for bile duct injury after bile duct surgery can prevent surgical reoperation and postoperative re-injury, which can endanger patients’ lives. At present, this technology in our gastrointestinal endoscopy unit is at the leading level in the province and surrounding provinces, and we actively assist local and provincial hospitals to promote and carry out this technology.