The precision radiation / immune synergistic therapy of tumors based on nano-selenium targeted design is a new therapeutic technology that uses nano-selenium as a radiosensitizer to produce a large amount of reactive oxygen species under X-ray stimulation, thus killing tumor cells. Nano selenium is a kind of high biocompatibility, low toxicity, high stability and tunability of nanomaterials, can through different synthesis methods and surface modification strategy, achieve targeted delivery and responsive release of tumor, and with other treatments such as immunotherapy, improve the efficiency and safety of tumor treatment. The precise radiation / immune-synergistic tumor therapy based on nano-selenium targeted design is a promising medical technology with the advantages of non-invasive, high efficiency, low toxicity and multifunction.