Insoluble aluminum salts such as aluminum (oxy)hydroxide are commonly used as vaccine adjuvants. Recently， there is evidence suggesting that the adjuvant activity of aluminum salt-based materials is tightly related to their physicochemical properties， including nanometer-scale size， shape with long aspect ratio， and low degree of crystallinity. Herein， for the first time， the bicontinuous reverse microemulsion (RM) technique was utilized to synthesize stick-like monodisperse aluminum (oxy)hydroxide nanoparticles with a long aspect ratio of ～10， length of ～80 nm， and low degree of crystallinity (denoted as Al-nanosticks). Moreover， the relationship between the physicochemical properties of Al-nanosticks and the bicontinuous RM was discussed. Compared to the commercial Alhydrogel， which contains micrometer-scale aluminum oxyhydroxide particular aggregates with moderate degree of crystallinity， the Al-nanosticks are more effective in adsorbing and delivering antigens (e.g.， ovalbumin， OVA) into antigen-presenting cells， activating inflammasomes， and potentiating OVA-specific antibody responses in a mouse model. It is concluded that the aluminum (oxy)hydroxide nanosticks synthesized in the bicontinuous RM are promising new aluminum salt-based vaccine adjuvants.