This review article discusses the research progress on emulsion-based vaccine adjuvants, focusing on their mechanisms of action and applications in vaccine development. Emulsion-based adjuvants, such as MF59, AS03, and others, are used to enhance the immunogenicity of vaccines, particularly recombinant protein or synthetic peptide vaccines, which are safer but less effective than traditional inactivated vaccines. These adjuvants improve immune responses by enhancing antigen presentation, increasing cytokine production, and promoting immune cell recruitment. MF59, approved by the FDA, is an oil-in-water emulsion that enhances humoral and cellular immunity. AS03, a water-in-oil emulsion, has been used in influenza vaccines and has shown strong immune responses. Other adjuvants, such as Pickering emulsions and DETOX, have also been studied for their potential in vaccine development. These adjuvants are effective in inducing immune responses, but they can also cause adverse reactions, such as local granulomas and systemic symptoms. The article highlights the importance of emulsion-based adjuvants in vaccine development, particularly in the context of pandemics. They offer advantages such as improved immunogenicity, reduced antigen doses, and the ability to respond to both homologous and heterologous strains. However, further research is needed to fully understand their mechanisms and to ensure their safety and efficacy. The development of emulsion-based adjuvants is crucial for the future of vaccine technology, especially in the fight against emerging pathogens like SARS-CoV-2. The review concludes that emulsion-based adjuvants have a promising future in vaccine development and are essential for the development of modern subunit and peptide vaccines.This review article discusses the research progress on emulsion-based vaccine adjuvants, focusing on their mechanisms of action and applications in vaccine development. Emulsion-based adjuvants, such as MF59, AS03, and others, are used to enhance the immunogenicity of vaccines, particularly recombinant protein or synthetic peptide vaccines, which are safer but less effective than traditional inactivated vaccines. These adjuvants improve immune responses by enhancing antigen presentation, increasing cytokine production, and promoting immune cell recruitment. MF59, approved by the FDA, is an oil-in-water emulsion that enhances humoral and cellular immunity. AS03, a water-in-oil emulsion, has been used in influenza vaccines and has shown strong immune responses. Other adjuvants, such as Pickering emulsions and DETOX, have also been studied for their potential in vaccine development. These adjuvants are effective in inducing immune responses, but they can also cause adverse reactions, such as local granulomas and systemic symptoms. The article highlights the importance of emulsion-based adjuvants in vaccine development, particularly in the context of pandemics. They offer advantages such as improved immunogenicity, reduced antigen doses, and the ability to respond to both homologous and heterologous strains. However, further research is needed to fully understand their mechanisms and to ensure their safety and efficacy. The development of emulsion-based adjuvants is crucial for the future of vaccine technology, especially in the fight against emerging pathogens like SARS-CoV-2. The review concludes that emulsion-based adjuvants have a promising future in vaccine development and are essential for the development of modern subunit and peptide vaccines.