Autoimmune diseases refer to a common category of diseases caused by the immune system reacting to self-antigens, leading to tissue damage. Autoimmune diseases encompass a wide variety of conditions, such as systemic lupus erythematosus, Sjögren's syndrome, systemic sclerosis, inflammatory myopathies, ANCA-associated vasculitis. Current treatments for autoimmune diseases include glucocorticoid, immunosuppressants, and biologics. B cell-driven humoral immune abnormalities are a central pathogenic mechanism in many autoimmune diseases. When autoreactive B cells are excessively activated, they produce large amounts of autoantibodies and immune complexes. These antibodies and immune complexes can cause damage to various tissues and organs, leading to the development of multiple autoimmune diseases. Therefore, targeting B cells to treat autoimmune diseases is an attractive therapeutic strategy. Clinical studies are exploring the use of CD19-targeting CAR-T cells for the treatment of autoimmune diseases, and their therapeutic efficacy has been demonstrated. In this study, we investigate the safety and efficacy of universal CD19-targeting CAR T cells in the treatment of autoimmune diseases.