Hilar cholangiocarcinoma (hCCA), also known as Klatskin tumor, is a malignant tumor that originates from the biliary epithelium between the secondary hepatic duct and the opening of the cystic duct. Surgery is the only potentially curative treatment for hCCA. The nature of the surgical margins is the most critical factor in the long-term survival of patients undergoing resection. However, as the most common subtype of cholangiocarcinoma, the pathological type of hCCA is mostly low to moderately differentiated adenocarcinoma, which is highly invasive and malignant, with no obvious early symptoms and no effective means of detection, so most patients are already at an advanced stage of the disease at the time of diagnosis and have lost the indication for surgery. Although neoadjuvant chemoradiotherapy combined with in orthotopic liver transplantation has been demonstrated to be an effective treatment modality for some locally advanced unresectable hCCA, it cannot become a treatment option for most patients because of the strict inclusion criteria, shortage of liver sources, and loss of transplantation condition in some patients due to tumor progression while waiting for liver sources. Although conventional chemoradiotherapy prolongs the survival time of patients with unresectable hCCA to some extent, its efficacy remains limited. Some researches have indicated that neoadjuvant chemoradiotherapy can downgrade a previously unresectable hCCA into a resectable one and improve the R₀ resection rate, but it lacks credibility because of the limited amount and obsolescence of the relevant data. With the advancement of technology, photodynamic therapy and new radiotherapy techniques including stereotactic radiotherapy, three-dimensional conformal radiotherapy and radioactive particle implantation have emerged, local treatment of hCCA has entered a more precise era. In recent years, with the development of genetic testing and in-depth research on tumor microenvironment, inhibiting tumor progression at the molecular biology level is a popular direction for research on various solid tumors. Targeted drugs for different targets and immune checkpoint inhibitors (PD1/PD-L1 antibodies, CTLA4 antibodies) have emerged and made rapid progress, providing a new direction for the treatment of unresectable hCCA. However, as far as the current research is concerned, although targeted therapy and immunotherapy have achieved excellent results in the treatment of intrahepatic cholangiocarcinoma, their performance in the treatment of hCCA is still unsatisfactory. A single treatment of unresectable hCCA is less effective, the combination of multiple treatment modalities is the focus of current research. This article mainly addresses the progress in the treatment unresectable hCCA and the feasibility of neoadjuvant therapy in achieving R₀ resection, hoping to provide some reference for the treatment of such patients.