Abstract: Radiotherapy, as a method for tumor treatment, refers to the utilization of ionizing radiation to cause direct or indirect damage to tumor cells. However, the effect of radiotherapy is limited because of the normal tissue damage and tumor radiation resistance of tumor cells. Tumor radiosensitization is a research hotspot in recent years, which aims to increase the sensitivity of tumors to radiotherapy, overcome the defects of radiotherapy and improve the efficacy of radiotherapy. Inorganic nanomaterial-mediated tumor radiosensitization can improve radiotherapy efficacy mainly by increasing intracellular radiation energy deposition, catalyzing the generation of reactive oxygen species and regulating the tumor microenvironment. This article reviews the research progress on inorganic nanomaterial-mediated tumor radiosensitization.