Abstract: Poly (adenosine diphosphate-ribose) polymerase inhibitor (PARPi) are one of the important anti-tumor targeting drugs, which is mainly used in the treatment of ovarian cancer and other malignant tumors. In recent years, studies have shown that PARPi can increase the efficacy of radiotherapy in many types of malignant tumors. The aruthors review the preclinical and clinical progresses of PARPi as radiosensitizers in the treatment of malignant tumors, providing evidence for clinical use of PARPi as radiosensitizer.