Congenital bile duct cyst, also known as “congenital cystic dilatation of the bile ducts”. It refers to a condition in which the bile ducts appear to be cystically dilated. Congenital cystic dilatation of the bile ducts is more common in women, with an incidence ratio of about 4:1 in women and men. Although it is a benign lesion, it brings a series of complications and is also a high risk factor for bile duct tumors. In patients with cystic dilatation of bile duct, the abnormal structure of the lower end of bile duct can lead to difficulty in bile excretion, which can lead to secondary stones in bile duct, and in severe cases, even necrotic perforation of bile duct, followed by acute peritonitis. When the bile duct cyst is huge and compresses the pylorus and duodenal bulb of the stomach, it can lead to impaired gastric emptying, resulting in loss of appetite, nausea, vomiting and other symptoms. In addition to these complications, the risk of biliary tumors accumulates with age, and the overall lesion rate is between 2% and 20%, while the overall probability of biliary tumors in normal population is less than 0.1%. In a sense, although congenital cystic dilatation of bile duct is a benign disease, it is also a precancerous lesion. Once the diagnosis is established, surgery should be carried out as soon as possible to remove the lesion and reconstruct the bile drainage channel. The treatment principle of congenital cystic dilatation of bile duct is: resection of the lesion and biliopancreatic diversion. The most commonly used surgical procedure is “bile duct cyst excision with bile duct jejunostomy Roux-en-Y anastomosis”. The cystic dilated bile duct tissue is removed as much as possible, and the bile and pancreatic fluid are shunted at the same time. 3. “Laparoscopic surgery” can also treat congenital cystic dilatation of bile ducts With the innovation of technology, laparoscopic surgery for congenital bile duct cysts has gradually become possible. The scope of laparoscopic resection and the basic principles of bile duct jejunostomy are the same as those of conventional surgery. However, for some patients with huge dilatation of the bile duct-pancreatic segment, there are some limitations in using laparoscopic surgery. The author has successfully performed laparoscopic choledochal cystectomy for several patients, and the quality of life of the patients after surgery is significantly improved because there is no large abdominal wound. 4. Long-term follow-up is still needed after surgery Whether it is laparoscopic surgery or traditional surgery, the probability of bile duct stones and bile duct tumors in patients with congenital cystic dilatation is significantly reduced after surgical treatment compared with that before surgery. However, since there is still a certain possibility of bile duct stones or bile duct tumors, patients should insist on regular hepatobiliary system checkups at the hospital, generally recommended every six months.