Objective: To investigate the application value of three-dimensional reconstruction of CT scan images in diagnosing and the resectability assessment of hilar cholangiocarcinoma. Methods: The clinical data of 15 patients with hilar cholangiocarcinoma treated in the Affiliated Provincial Hospital of Anhui Medical University from January 2015 to December 2016 were retroprospectively studied. Before operation, all patients underwent three-dimensional CT reconstruction, and the locations of the tumors and their relations with the surrounding structures as well as their Bismuth classifications were analyzed and thereafter, the surgical resectabilities of the tumors were judged. Results: Of the 15 patients, all cases underwent surgical exploration; Bismuth classification was type II tumor in one case, type III tumor in 5 cases (type IIIa in 2 cases and IIIb in 3 cases) and type IV tumor in 9 cases respectively; 11 cases underwent radical operation and 4 patients had palliative resection. The diagnostic accuracy of three-dimensional CT reconstruction for tumor classification, and tumor relation with the portal vein and the hepatic artery, and mass volume was 93.3%, 86.7%, 53.3% and 93.3%, respectively. The coincidence rate of preoperative simulation operation and actual operation was 80%. Conclusion: The preoperative three-dimensional CT reconstruction can accurately, directly and dynamically display the hilar cholangiocarcinoma and its three-dimensional relations with adjacent structures, and has high accuracy in judging the resectability of the hilar cholangiocarcinoma. So it is recommended to be used in clinical practice.