Endoscopic duodenal sphincterotomy is a new treatment function of the electronic duodenoscope (commonly known as “cholelithiasis in the mouth”) and is an important part of minimally invasive biliary surgery. Traditional treatment of bile duct stones, septic cholangitis, biliary tract ascariasis, pancreaticobiliary stenosis, and papillary stenosis has been performed by open surgery. With the emergence of new equipment and technology, the means of treatment of biliary diseases has undergone significant changes. Jaundice and pain caused by pancreaticobiliary diseases can be easily solved by inserting duodenoscope through the mouth and performing minimally invasive surgery under the mirror, without dissection and open surgery, with little pain: 1. stones less than 1cm in diameter can be discharged naturally after EST. 2.Stones of 1-2cm in diameter can be removed directly by using a lithotripsy basket. 3.Stones larger than 2cm can be discharged after lithotripsy.