CarT therapy (CAR-T therapy), or chimeric antigen receptor T-cell immunotherapy, is one of the immunotherapies that are mainly used in the clinical treatment of patients with malignant hematological diseases and malignant tumors. CAR-T therapy is based on the collection and isolation of T cells from patients’ blood, followed by genetic modification to enhance their targeting and killing ability against cancer cells. CAR-T therapies are more lethal to tumor cells, and are more targeted and longer lasting. Each CAR-T is purposely designed according to the surface antigens of the tumor in the patient’s body, and is therefore more targeted. Experiments have demonstrated that these genetically modified T cells can still exert anti-tumor activity when cancer cells in the body resurface from the dead. This treatment can be applied to the treatment of hematological tumors as well as solid tumors, such as leukemia, lymphoma, multiple myeloma, glioma, neuroblastoma, etc. Of course, it should also be clear that this treatment also has certain adverse effects, the most serious of which is cytokine release syndrome, in which patients usually present with high fever, nausea, hypotension, and respiratory distress. In severe cases, neurotoxic manifestations such as epilepsy and coma may also occur. This therapy has not been widely used in the clinic for the time being. On the one hand, the reason is that the CAR-T cell preparation procedure is complicated and the technical threshold is high; on the other hand, CAR-T cells currently have poor efficacy in solid tumors, and numerous CAR-T clinical trials for solid tumors are underway, with the expectation that various technologies will be used to create more efficient CAR-T cells to seek breakthroughs in solid tumors. The good news is that the first CAR-T drug for relapsed refractory diffuse large B-cell lymphoma was recently approved for marketing in China, which may further advance the clinical application of CAR-T therapy.