Generally, the diameter of the common bile duct is less than 1 cm, but if the diameter of the common bile duct exceeds 1.2 cm, it is clinically called dilated. Whether the common bile duct is dilated or not is a very important reference indicator for whether to perform common bile duct exploration in clinical surgery. The indications for common bile duct exploration include the following: 1) Patients with biliary pancreatitis, because the pancreatitis caused by biliary pancreatitis is fundamentally a problem of the bile duct, so common bile duct exploration must be performed. 2) Patients with acute suppurative cholangitis must undergo choledochotomy. 3) Patients with stones or roundworms or even tumors that can be found in the common bile duct must undergo choledochotomy. 4.After severe liver trauma or liver resection, and extrahepatic bile duct repair or anastomosis, bile ducts should be drained by bile duct incision, and the bile ducts should be repaired and reconstructed as appropriate to avoid biliary strictures.