The article reviews the research progress on emulsion-based vaccine adjuvants, focusing on their mechanisms of action and clinical applications. Emulsion adjuvants, such as MF59, AS03, and Pickering emulsion, have been widely studied for their ability to enhance the immunogenicity of vaccines. These adjuvants work by recruiting immune cells, stimulating antigen presentation, and modulating cytokine production at the injection site and in draining lymph nodes. MF59, a water-in-oil emulsion, is particularly effective in inducing Th2 immune responses and has been used in various vaccines, including influenza, hepatitis B, and HIV. AS03, another water-in-oil emulsion, combines QS-21 and MPL to enhance both humoral and cellular immune responses. Pickering emulsions, which use alum as a stabilizer, are surfactant-free and have shown promise in inducing strong humoral and cellular immunity against SARS-CoV-2. The article also discusses the safety and efficacy of these adjuvants, highlighting their potential in pandemic responses and the ongoing development of new vaccine formulations. The combination of different adjuvants and the optimization of antigen structures are seen as promising directions for future research to improve vaccine safety and efficacy.The article reviews the research progress on emulsion-based vaccine adjuvants, focusing on their mechanisms of action and clinical applications. Emulsion adjuvants, such as MF59, AS03, and Pickering emulsion, have been widely studied for their ability to enhance the immunogenicity of vaccines. These adjuvants work by recruiting immune cells, stimulating antigen presentation, and modulating cytokine production at the injection site and in draining lymph nodes. MF59, a water-in-oil emulsion, is particularly effective in inducing Th2 immune responses and has been used in various vaccines, including influenza, hepatitis B, and HIV. AS03, another water-in-oil emulsion, combines QS-21 and MPL to enhance both humoral and cellular immune responses. Pickering emulsions, which use alum as a stabilizer, are surfactant-free and have shown promise in inducing strong humoral and cellular immunity against SARS-CoV-2. The article also discusses the safety and efficacy of these adjuvants, highlighting their potential in pandemic responses and the ongoing development of new vaccine formulations. The combination of different adjuvants and the optimization of antigen structures are seen as promising directions for future research to improve vaccine safety and efficacy.