Biliary tract malignancies is a malignancy with insidious onset, low surgical resection rate, poor prognosis and unsatisfactory chemotherapy effects. With the continuous in-depth study, combined immunotherapy based on immune checkpoint inhibitors (ICIs) has gradually become an important direction for the treatment of biliary tract malignancies. Several clinical trials have conducted in-depth exploration of ICIs alone and in combination with first-line chemotherapy regimens or targeted drugs or double immunization regimens for biliary malignant tumors. The results show that ICIs monotherapy exhibits certain efficacy, albeit with significant variations in treatment outcomes. The combination of ICIs with first-line chemotherapy has now become the standard treatment protocol. Furthermore, the " triple-drug and quadruple-therapy regimen" involving ICIs in conjunction with chemotherapy and molecular targeted therapy holds promise as a potential new standard for BTC treatment. Additionally, dual immunotherapy combinations are gradually being implemented in clinical trials. In the present article, we provides an in-depth elaboration of the current status of clinical research on immune checkpoint inhibitors and their combination therapy in advanced biliary tract malignancies.