Objective: To evaluate the clinical efficacy of this method in the treatment of type IV and Bismuth bile duct carcinoma by Y biliary stent combined with ¹²⁵I particle implantation. Methods: The clinical data of 12 patients with IV type bile duct carcinoma who lost the time of radical surgery or could not tolerate surgical treatment in Weifang Hospital of Traditional Chinese Medicine were analyzed retrospectively. The curative effect and complications were analyzed. Results: All 12 patients were all successful surgery. The stent and ¹²⁵I particles were implanted successfully according to preoperative plan. After DSA monitoring, the biliary obstruction disappeared and the bile duct was unobstructed. The success rate of operation was 100%; postoperative jaundice disappeared, total bilirubin and other indexes decreased or decreased to normal range; 1 months later, the total bilirubin was statistically different from that before operation (t=9.335, P<0.001), and the direct bilirubin value was statistically different from that before operation (t=7.325, P<0.001), the median patency period of 19 months, the median survival time was 17 months. The two items of CEA and CA199 were reduced in varying degrees, and 5 cases were recovered to the normal range. Except for 1 patient with unexplained ascites, no complications such as stent and/or particle translocation and radiation injuries were found during the follow-up period. Conclusion: Y biliary stent combined with ¹²⁵I seeds implantation is feasible for the treatment of type IV cholangiocarcinoma. It is a safe and effective minimally invasive treatment, and can be used as a routine treatment regimen.