Abstract: Tumor immunotherapy is mainly through lifting immunosuppression and enhancing immune response to achieve effective treatment. Nanotechnology can improve the aggregation degree and force of immune-stimulating molecules and effectively treat cancer on the basis of completing local immune regulation. The chimeric antigen receptor-modified T (CAR-T) is a powerful means in tumor immunotherapy, it can carry on the transformation of T cells in patients with tumor treatment, become CAR-T cells expressing chimeric tumor cell surface antigen receptors. Afterwards, the corresponding CAR-T cells were back to the body of cancer patients, and the tumor virus was effectively killed by specific recognition and killing tumor cells. The application of nanotechnology in CAR-T tumor immunotherapy is expected to improve the efficacy and safety of tumor immunotherapy. This paper reviewed the application of nanotechnology in the tumors immunotherapy of CAR-T.