Choledochal cyst is one of the most common congenital biliary malformations in clinical practice. It refers to such a congenital malformation in which a portion of the common bile duct is cystically or syrinely dilated, sometimes accompanied by dilatation of the intrahepatic bile duct. The name of this condition still has various names. For example, congenital common bile duct cyst, common bile duct cyst, congenital common bile duct dilatation, primary common bile duct dilatation or giant bile duct disease, etc. In recent years, in-depth studies on the pathology, morphology, and etiology of this disorder have revealed that in addition to cystic dilatation of the common bile duct, about half of the patients present with only a shuttle-shaped or cylindrical dilatation of the common bile duct, rather than a giant cyst. In addition to extrahepatic dilatation of the common bile duct, about 1/4 of the cases also combined with dilatation of the intrahepatic bile duct, which can be shuttle-shaped or even small cyst-like dilatation. Therefore, recently, there is a general tendency at home and abroad that it is more reasonable to call the disease congenital bile duct dilatation, which can more comprehensively reflect the pathological changes of the disease and better accommodate the multiple aspects of the disease.