Endoscopic retrograde cholangiopancreatography (ERCP) is a more mature minimally invasive interventional technique, which involves inserting an endoscope into the descending duodenum, finding the duodenal papilla, inserting a catheter through the endoscopic biopsy orifice to the opening of the papilla, the bile duct or the pancreatic duct, and injecting a contrast agent for X-ray cholangiopancreatography, which is an important tool for clinical diagnosis and treatment of diseases of the liver, biliary and pancreatic systems, and is popular among patients because of its small trauma, quick recovery and short hospitalization. It is popular among patients because of its small trauma, quick recovery and short hospitalization time. Indications: It is generally considered that all suspected biliary and pancreatic diseases are indications, including: 1. suspected bile duct stones, tumors or obstructive jaundice of unknown origin; 2. suspected pancreatic tumors, malignant tumors of duodenal papilla or jugular abdomen; 3. suspected biliary pancreatitis, chronic pancreatitis or recurrent pancreatitis of unknown origin; 4. recurrent right upper abdominal pain or jaundice after cholecystectomy or bile duct surgery; 5. 6. gallbladder stones to be laparoscopically resected, excluding common bile duct stones; 7. biliary tract infection and biliary obstruction requiring nasobiliary or internal stent drainage to reduce yellowing; 8. unexplained epigastric pain excluding biliopancreatic disease; 9. suspected biliary bleeding; 10. suspected pancreatic duct rupture and pancreatic leakage after pancreatic trauma. Contraindications: 1. upper gastrointestinal stenosis or obstruction, and it is estimated that the endoscope cannot reach the descending duodenum; 2. severe cardiopulmonary insufficiency; 3. acute pancreatitis of non-biliary origin. Preoperative preparation: 1. Pharyngeal anesthesia is the same as gastroscopy, fasting for 6-8 hours before surgery, iodine allergy test; 2. Instrument preparation: lateral duodenoscope, disposable treatment accessories (incisional knife, guidewire, dilating balloon, lithotomy balloon, nasobiliary tube, plastic stent, etc.); 3. Preoperative medication: Valium 10mg, antispasmodic spirit or scopolamine 10mg, morphine or tramadol 5-10mg. Postoperative management: 1. After successful imaging, to prevent infection of bile duct and pancreatic duct, routinely apply antimicrobial agents for 3-7 days; 2. 3 hours and 24 hours postoperative blood sampling for routine blood tests, blood amylase and lipase, and continue to recheck those who are elevated until they return to normal; 3. Observe for fever, jaundice, abdominal pain, etc.; 4. Fasting, water fasting, and gradually enter liquid, semi-liquid, and general diet after the patient’s blood amylase returns to normal.