A tannic acid-based nanomaterial is engineered to address rheumatoid arthritis by promoting antigen-specific immune tolerance. This nanovaccine, designed for targeted delivery of dexamethasone and citrullinated peptide, utilizes a lipid-coated nanoparticle with tannic acid as its core material (CitDTN). The surface of CitDTN is modified with abatacept, resulting in AbaCitDTN. This modification enables AbaCitDTN to target dendritic cells by interacting with co-stimulatory molecules CD80 and CD86. Upon subcutaneous administration, AbaCitDTN exhibits increased accumulation in lymph nodes. AbaCitDTN alters the characteristics of dendritic cells towards tolerogenic phenotypes and disrupts co-stimulatory signals between dendritic cells and T cells, leading to reduced T cell proliferation and interleukin-2 secretion. In the collagen-induced arthritis model, AbaCitDTN is administered subcutaneously on a weekly basis for a total of four injections. The in vivo administration of AbaCitDTN results in improved clinical symptoms and joint protection in this model. These findings underscore the potential of nanomaterials in inducing antigen-specific immune tolerance for the treatment of rheumatoid arthritis.