DNA vaccines have shown promise in treating both genetic and acquired diseases, but their effectiveness is limited by the lack of an optimal delivery system. This review discusses the current status and challenges of DNA vaccines, focusing on both viral and non-viral delivery systems. DNA vaccines are genetically engineered DNAs that serve as templates to transmit molecular information and trigger antigen-specific immune responses. They encode the target antigen and rely on an effective delivery system to introduce the target antigen gene and express the corresponding protein for immune response activation. The review evaluates the strengths and weaknesses of various delivery systems, including viral vectors such as adenovirus, adeno-associated virus, retroviruses, and lentiviruses, and non-viral vectors such as liposomes, cationic polymers like polyethyleneimine (PEI), and chitosan. The review also summarizes recent advancements and breakthroughs in preclinical and clinical studies, highlighting the need for further clinical trials in this rapidly evolving field. The review discusses the advantages of DNA vaccines, including low manufacturing cost, easy production, high stability, and a good safety profile. However, concerns about the potential risk of integrating the host genome have been raised. Despite these concerns, DNA vaccines are designed to minimize the risk of genetic integration. The review also discusses the role of adjuvants and nanocarrier modifications in enhancing the immunogenicity of DNA vaccines. The review highlights the importance of optimizing the delivery system to maximize the immunogenicity of DNA vaccines and improve their stability and immune response. The review also discusses the action mechanism of DNA vaccines, including the recognition of DNA vaccines by pattern recognition receptors (PRRs) of the innate immune system, leading to the activation of innate immune responses, and the effective presentation of antigens to CD8+ T cells in the form of major histocompatibility complex (MHC) class I complexes. The review also discusses the role of various delivery systems in facilitating the transport of DNA to the nucleus for processing and the subsequent immune response. The review concludes that DNA vaccines have the potential to be highly effective in treating various diseases, but further research is needed to address the challenges associated with their development and application.DNA vaccines have shown promise in treating both genetic and acquired diseases, but their effectiveness is limited by the lack of an optimal delivery system. This review discusses the current status and challenges of DNA vaccines, focusing on both viral and non-viral delivery systems. DNA vaccines are genetically engineered DNAs that serve as templates to transmit molecular information and trigger antigen-specific immune responses. They encode the target antigen and rely on an effective delivery system to introduce the target antigen gene and express the corresponding protein for immune response activation. The review evaluates the strengths and weaknesses of various delivery systems, including viral vectors such as adenovirus, adeno-associated virus, retroviruses, and lentiviruses, and non-viral vectors such as liposomes, cationic polymers like polyethyleneimine (PEI), and chitosan. The review also summarizes recent advancements and breakthroughs in preclinical and clinical studies, highlighting the need for further clinical trials in this rapidly evolving field. The review discusses the advantages of DNA vaccines, including low manufacturing cost, easy production, high stability, and a good safety profile. However, concerns about the potential risk of integrating the host genome have been raised. Despite these concerns, DNA vaccines are designed to minimize the risk of genetic integration. The review also discusses the role of adjuvants and nanocarrier modifications in enhancing the immunogenicity of DNA vaccines. The review highlights the importance of optimizing the delivery system to maximize the immunogenicity of DNA vaccines and improve their stability and immune response. The review also discusses the action mechanism of DNA vaccines, including the recognition of DNA vaccines by pattern recognition receptors (PRRs) of the innate immune system, leading to the activation of innate immune responses, and the effective presentation of antigens to CD8+ T cells in the form of major histocompatibility complex (MHC) class I complexes. The review also discusses the role of various delivery systems in facilitating the transport of DNA to the nucleus for processing and the subsequent immune response. The review concludes that DNA vaccines have the potential to be highly effective in treating various diseases, but further research is needed to address the challenges associated with their development and application.