There are many complications of ERCP (endoscopic retrograde cholangiopancreatography), and the common ones include postoperative pancreatitis, hemorrhage, perforation, cholangitis, cholecystitis, etc. The most common complication of ERCP is severe abdominal pain with elevated blood amylase. 1. Postoperative pancreatitis: it is the most common complication of ERCP, manifested as severe abdominal pain with elevated blood amylase, which is related to intraoperative biliary sphincter dilatation. 2. Bleeding: Bleeding is uncommon in diagnostic ERCP, but common in therapeutic ERCP that requires sphincterotomy, with black stools, decreased hemoglobin, etc. Hemostasis and transfusion are needed if necessary. 3. Perforation: it mainly includes perforation caused by guide wire, perforation around the jugular abdomen in papillotomy and perforation away from the papilla. Generally, it is found quickly and then biliary and duodenal fluid drainage is carried out, and the use of ceftriaxone and other antibiotics can avoid reoperation. 4. Cholangitis: the occurrence of cholangitis is related to ERCP combined with percutaneous endoscopic operation, stent placement, and incomplete bile drainage, etc. Generally, the incomplete stone removal can be prevented by performing nasobiliary drainage. 5. Cholecystitis: cholecystitis occurs less often, mainly related to the presence of gallbladder stones, cholecystography. ERCP can be used to treat many biliary and pancreatic diseases, and patients are advised to consult with a specialist to weigh the pros and cons of choosing the appropriate treatment. The procedure should be performed carefully to minimize complications.