PTCD refers to percutaneous hepatic puncture cholangiopancreatic drainage, a minimally invasive technique that involves percutaneous hepatic puncture of the bile ducts, prior imaging, and setting up a drainage tube for drainage. Its main purpose is to relieve bile duct hypertension, drain pus to control infection, and also to drain bile and reduce bilirubinemia. Clinically, it is mainly applied in the following cases: 1. For patients with obstructive jaundice, preoperative drainage to reduce bilirubin can reduce postoperative complications, thus reducing the morbidity and mortality rate. 2. For patients with acute suppurative cholangitis, PTCD can be performed in an emergency if there is shock, renal insufficiency, and impaired consciousness that cannot tolerate surgery. 3. For the palliative treatment of patients with advanced bile duct cancer. 4. patients with biliary-derived liver abscess, infection control can be achieved by drainage.