Abstract: Malignant tumor is a serious threat to human health, and its early diagnosis and treatment is the key factor to improve the survival rate of cancer patients. The nanocarrier system of nuclear medicine then comes into being, which meets the needs of medical research and clinical medicine on malignant tumor diagnosis and treatment at the present stage. By labeling nanomaterials with radionuclide ¹³¹I, the advantages of nanomaterials, such as small particle size and surface modification, can be fully utilized to realize visualization of key molecules in the process of tumor formation, so as to achieve the goal of early diagnosis. At the same time, the targeted concentration of ¹³¹Ican be increased to the greatest extent, and the therapeutic effect of radionuclides themselves can be maximized, thus creating a new model of tumor diagnosis and treatment integration. The application of different nanomaterials labeled with radionuclide ¹³¹I in tumor diagnosis and treatment was reviewed.