Extrahepatic cholangiocarcinoma (eCCA) is a highly aggressive malignant tumor originating from the epithelial cells of the extrahepatic bile duct. Surgical resection with negative margins (R₀) is the most optimal treatment for eCCA patients. However, most patients have already lost the opportunity for radical surgical treatment at the time of initial diagnosis. Currently, palliative therapies such as radiation and chemotherapy yield poor results and come with significant adverse reactions. While biliary stenting, immunotherapy, and targeted therapy have particular efficacy, they also have limitations. Photodynamic therapy, as an emerging minimally invasive interdisciplinary technique with good tolerability and minimal side effects, not only inhibits tumor growth but also, in combination with various treatment modalities, enhances the survival and quality of life for unresectable eCCA patients. Therefore, it holds promising clinical prospects. This article mainly summarizes the mechanisms of photodynamic therapy, the current application status of light sources and photosensitizers, and combined treatments in clinical practice. Additionally, potential strategies to address the current clinical challenges of photodynamic therapy in treating eCCA are proposed to provide a basis and reference for clinical treatment options for eCCA patients and its research directions.