Self-adjuvanted vaccine delivery platforms possess potential for targeted delivery of antigens and initiation of potent immune responses. Although aluminum-containing adjuvants have been approved and widely used in human vaccines, their effectiveness in inducing Th1-type immune responses is far from satisfactory. To facilitate antigen delivery and activate potent antitumor immune responses, a self-adjuvanted nanovaccine (CPBG-Al@OVA) is constructed by functionalizing aluminum hydroxide with β-1,3-glucan, which recognizes pattern recognition receptors via Dectin-1. Carboxymethyl-phosphorylated β-1,3-glucan (CPBG) has been synthesized and optimized to achieve superior adjuvanticity while maintaining water solubility. CPBG then self-assembles with aluminum hydroxide and the targeted antigen, leading to the formation of a nanovaccine CPBG-Al@OVA. Owing to the favorable nanoscale size distribution, CPBG-Al@OVA effectively drains to the lymph nodes and is internalized by antigen-presenting cells (APCs) through Dectin-1-mediated endocytosis, activating the Syk and Raf1 signaling pathways and leading to upregulated TNFSF15 and OX40L expression to activate APCs. Following immunization, CPBG-Al@OVA activates potent CD8