Abstract: Heavy ion radiation is characterized by its unique physical dose deposition and superior biological effects. It not only offers significant advantages in precise local tumor killing and control but also modulates immune-related molecules and signaling pathways through mechanisms such as the DNA damage response, thereby enhancing tumor immunogenicity and reshaping the tumor immune microenvironment. The authors focus on novel radiotherapy approaches based on heavy ion radiation, systematically delineating their immune-stimulatory mechanisms and related molecular characteristics. Particular emphasis is placed on the synergistic effects between heavy ion radiation and immunotherapies such as immune checkpoint inhibitors, summarizing the latest clinical and preclinical research findings. The combination of the novel radiotherapy modality based on heavy ion radiation and immunotherapy has shown great potential for clinical translation. It will drive tumor treatment toward a more personalized and precise direction and is expected to become a frontier in tumor radiotherapy research.