The full name of ERCP procedure is transendoscopic retrograde cholangiopancreatography. Indications include: i. Jaundice caused by biliary obstruction. ii. Clinical laboratory or imaging tests that support diseases of the pancreas or biliary tract, including stones, tumors, sclerosing cholangitis, etc. III. Diseases of the pancreas, including pancreatic tumors, chronic pancreatitis, pancreatic abscesses, etc. IV. Pancreatitis of unknown origin. V. Sphincter of Oddi lesions. VI. Tissue biopsy of the pancreatic duct or bile duct. In addition, it should be emphasized that due to the advancement of CT, ultrasound endoscopy and MRI imaging of the pancreaticobiliary duct, purely diagnostic ERCP is rarely used at present.