Congenital common bile duct cyst, a relatively common biliary malformation in children, is found in about 60% of infants and toddlers. It is more common in females than males, approximately 4 to 5:1. Symptoms can occur at any age. The disease is a congenital developmental malformation, and abnormal pancreaticobiliary duct coaptation is one of the recognized causes. There are also theories of biliary epithelial proliferation imbalance, viral infection, and genetic factors. Abdominal pain, mass and jaundice are the three basic symptoms of the disease, and the symptoms are mostly intermittent. (i) Abdominal pain: it occurs mostly in the middle of the epigastrium, and the nature and degree of pain varies. ②Lumps: larger cysts are easily palpable. ③ Jaundice: obstructive jaundice caused by biliary outlet obstruction, and in mild cases there may be no jaundice. Choledochal cyst excision with jejunal common hepatic duct Roux-Y anastomosis is the classic procedure for this disease. For individual severe cases or those with cyst perforation, external drainage can be performed first, and then cyst excision and bile duct reconstruction can be performed after the condition is stabilized. For children with combined pancreatitis and severe inflammation around the cyst, radical surgery can be performed only after the inflammation is well controlled. At present, the most advanced international surgical method is laparoscopic resection of common bile duct cyst plus Roux-Y anastomosis of the common jejunohepatic duct, which has the advantages of less trauma, faster recovery, less pain and less scarring on the abdominal wall. This technique has been widely carried out in our department with more than 30 cases so far with satisfactory results.