ERCP, known as endoscopic retrograde cholangiopancreatography, is a procedure performed through an endoscope. The endoscopic retrograde cholangiopancreatography is a procedure in which a duodenoscope is inserted into the descending part of the duodenum to locate the duodenal papilla, and then a contrast catheter is inserted into the biopsy tube to the opening of the papilla, and then after injecting the patient with a contrast medium, an x-ray examination is performed to visualize the pancreatic and biliary ducts. It can be used for the diagnosis of choledochal diseases, and for the removal of choledochal stones. It can also be used for the treatment of cholangiocarcinoma and pancreatic head cancer. Transendoscopic retrograde cholangiopancreatography is characterized by no incision, little trauma and short operation time. For patients with choledocholithiasis, it may cause sphincter dysfunction, leading to bile duct reflux and cholangitis. ERCP surgery, should be under the doctor’s advice, in conjunction with their own conditions to avoid delay.