CAR-T cell therapy is a form of adoptive T-cell immunotherapy. CAR consists of 3 domains: intracellular, transmembrane and extracellular. Intracellular domain recognizes the target antigen. Transmembrane domain connects the other two domains. Extracellular domain provides signals for the activation of lymphocytes after binding to the antigen, and based on it, CAR-T cells are divided into 5 generations. The therapy process itself is demanding and expensive, but only one dose is needed. It begins with leukapheresis and selection of the desired T lymphocytes, followed by the introduction of the CAR transgene and expansion of cells ex vivo using cytokines, ending with the reinfusion of cells into the individual. It is most effective in the treatment of hematological malignancies, and for such cancers, the FDA has approved 6 therapies, four of which are designed with CARs targeting CD19 and two targeting BCMA. For the treatment of solid tumors, many preclinical and clinical studies are intensively carried out, with challenges in finding the appropriate target antigen, delivering CAR-T cells to the tumor site and dealing with the immunosuppressive tumor microenvironment. Recently, more and more attention has been given to the application of CAR-T therapy for treating autoimmune diseases. On the one hand, CAAR-T cell immunotherapy is being developed, the goal of which is to specifically eliminate autoreactive B lymphocytes, and on the other, CAR-Treg, which aims to restore the immunological tolerance.