Gao**, a 2-year-old 11-month-old boy, began to have abdominal pain six months ago. The local hospital considered common bile duct stones, but did not exclude the possibility of abnormal bile duct development or congenital bile duct cysts. The child’s parents came to our hospital after many inquiries and were referred by the doctor. After admission, the child’s imaging was further improved, and MRCP examination showed that the diagnosis of common bile duct stone was basically clear, but there might be terminal stenosis of the common bile duct and tortuous and disordered bile ducts in the hepatoportal area. The parents decided to use the ERCP technique to treat the child after combining the advantages and disadvantages of various treatment options offered by the hospital. It was decided that ERCP cholangiography should be used first to further clarify the diagnosis, and then re-evaluated based on the results of the imaging. The ERCP procedure in this case can only be performed with an adult duodenoscope, which is coarse, and because of the delicate tissue of the gastrointestinal mucosa and duodenal papilla in young children, the operation is risky and there is a possibility of intraoperative gastrointestinal perforation and postoperative pancreatitis. Before the operation, Director Zhang Californian organized another case discussion within the department to determine an individualized ERCP treatment plan for the young child, and discussed and prepared the anesthesia, possible medical risks, medical accidents and emergency treatment plan with the anesthesia department. After sufficient preparation, on February 3, the child was operated by Director Zhang Cf. Considering that the stenosis of the end of the common bile duct was a relative stenosis of the pancreatic segment, which did not affect the physiological function of the child, and that the distortion of the bile duct in the hilar region was a secondary manifestation of bile duct dilatation, and that the child’s bile was viscous with a large amount of turbid bile sludge, which was suitable for further treatment by ERCP, a small papillotomy of 2 mm was performed, and one small stone of the common bile duct was successfully removed, and the bile duct was cleaned and a biliary stent was placed. At the same time, to ensure that the biliary stent could be discharged by itself, a pancreatic stent was placed instead after intraoperative discussion. The whole operation was very smooth and lasted 25 minutes without bleeding. The child recovered well after surgery without any complications. He started to eat on the same day and was discharged from the hospital 5 days after the operation. By implementing this technique, the child avoided the pain of opening the abdomen, had less pain and faster recovery than surgical treatment, and achieved good results. The youngest patient in the history of ERCP surgery was a 4-year-old girl, who was only 2 years and 11 months old. It is rare in China to perform ERCP surgery on a patient of this age, which once again set a new record for the youngest age of ERCP surgery in our hospital.