Radiotherapy is a crucial component of the treatment of tumors. In addition to directly causing DNA damage in tumor cells and inducing cell apoptosis，radiotherapy is also involved in the regulation of systemic immune status. Increasing evidence indicates that radiotherapy can remodel the tumor immune microenvironment （TIME） and reverse the immunosuppressive state，thereby enhancing anti-tumor effects and demonstrating stronger immune responses and therapeutic benefits when combined with immune checkpoint inhibitors. Taking lung cancer as an example to explore the impacts and potential mechanisms of radiotherapy on the TIME and anti-tumor immunity，which can provide a scientific basis for optimizing the treatment strategies of lung cancer.