Abstract: Chimeric antigen receptor T cell (CAR-T) therapy is a novel adoptive cell therapy, and has received extensive attention in the field of tumor therapy in recent years, especially in the treatment of hematological tumors, such as acute lymphoblastic leukemia and diffuse large B-cell lymphoma. However, its application in solid tumors is limited because of the complex tumor microenvironment and target specificity. Molecular imaging based on radionuclides can better realize the visualization and therapeutic monitoring of CAR-T cells, and reflect the functional information and immune status of CAR-T cells, which has important guiding significance for the prediction and safety evaluation of CAR-T cells. This review will systematically introduce the latest advances in the application of radionuclide based molecular imaging strategies in CAR-T therapy.