Abstract: Glioma is the most common primary intracranial tumor, and most patients present as glioblastoma, with high morbidity and mortality. The prognosis of patients with glioblastoma remains poor after surgical resection combined with standardized treatment of radiotherapy and chemotherapy. In recent years, although the breakthrough of immunotherapy have been achieved in the treatment of a variety of solid tumors, the existing data show that immunotherapy is not effective in improving the survival of patients with glioblastoma. However, studies have shown that immunotherapy can have a synergistic effect with radiotherapy which can increase antigen presentation and promote the formation of pro-inflammatory tumor microenvironment, providing more relevant targets for immunotherapy. The purpose of this paper is to discuss the effect of radiotherapy on tumor immune microenvironment and the role of radiotherapy combined with immune checkpoint inhibitors in the treatment of glioblastoma.