Choledochal cysts are relatively rare in clinical practice, but they should be treated promptly with surgery, which is mainly performed by cystectomy and biliary-intestinal anastomosis. Some patients with choledochal cysts not only have a good quality of life, but also have a very satisfactory survival period, and can obtain long-term survival, such as surviving 20 or 30 years, or even close to that of the normal population. However, there are also some patients with postoperative choledochal cysts, due to the repeated stimulation of digestive juices and food residues, which will eventually lead to the formation of stones in the common bile duct, and also cause recurrent biliary duct infections, and even eventually cause the occurrence of bile duct cancer. These will not only affect the quality of life of patients, but also seriously affect their survival period. Cholangiocarcinoma is a digestive tumor with very high malignancy, and even with surgical treatment, the five-year survival rate may not exceed 30%, and many patients are likely to die within 1-2 years.