ERCP is the conjugation of the initials of the word retrograde endoscopic cholangiopancreatography, which is a contrast technique to retrograde the pancreaticobiliary duct by injecting contrast agent through the duodenal papilla under the endoscope, and is currently recognized as the gold standard for the diagnosis of pancreaticobiliary duct disease. On the basis of ERCP, interventions such as duodenal papillary sphincterotomy (EST), endoscopic nasal bile drainage (ENBD) and endoscopic internal bile drainage (ERBD) can be performed, which are popular among patients because they do not require incision, are less invasive and have a much shorter hospital stay. ERCP has been used in clinical practice in China for more than 20 years. It plays an increasingly important role in the diagnosis and treatment of pancreatic and biliary tract diseases as a minimally invasive treatment combined with duodenal endoscopic interventional techniques. The main indications of ERCP surgery are introduced to the patients: (1) Bile duct stones: after removing bile duct stones by duodenal endoscopy, it can replace the traditional dissection bile duct extraction and T-tube drainage without opening the abdomen, which is less traumatic and can prevent the recurrence of stones. (2) Residual bile duct stones after cholecystectomy: the stones can be removed endoscopically to avoid the pain of re-operation. (3) Acute biliary-derived severe pancreatitis: endoscopic nasobiliary drainage in 1-3 days in the early stage can improve the success rate of treatment. (4) Septic cholangitis: high mortality rate and high risk of traditional surgery, timely endoscopic biliary drainage for decompression can rapidly stabilize the patient’s condition and gain valuable time for surgical treatment. (5) Duodenal papillary cancer: early diagnosis is difficult, ERCP is clear at a glance and biopsy is possible. (6) Chronic pancreatitis and pancreatic duct stones. (7) Obstructive jaundice caused by bile duct cancer or pancreatic head cancer: stent therapy is feasible to resolve jaundice, delay liver failure and greatly prolong survival. Contraindications to ERCP: (1) those with upper gastrointestinal stenosis or obstruction, and it is estimated that it is impossible to reach the descending duodenum; (2) those with other contraindications to endoscopy such as cardiopulmonary insufficiency; (3) non-stone embedded acute pancreatitis or acute attack of chronic pancreatitis; (4) those with bile duct stenosis or obstruction and do not have bile duct drainage techniques. For those who are allergic to iodine, non-ionic contrast agents can be used instead, and preoperative emergency preparations should be made.