The invention relates to an antigen and TLR agonist targeting co-loaded cationic phospholipid-polymer hybrid nanoparticle vaccine adjuvant, and a preparation method and an application thereof. A hydrophobic inner core is encapsulated with a TLR7 agonist, a phospholipid layer is encapsulated with a TLR4 agonist, an antigen is adsorbed by cationic phospholipids in the phospholipid layer, and ligation of a mannose ligand makes the vaccine adjuvant like a specific targeting antigen to have the dendritic cell presenting ability, so the DC cell intake and the maturation promoting effect are enhanced; and the antigen is protected by hybridized nanoparticles, the antigen uptake by DC cells is improved, immune response after antigen stimulation is significantly enhanced by the TLR agonist, and thecross-presentation of the antigen is significantly improved, so vaccine adjuvant has a strong potent T cell killing effect, can induce cytokine secretion, has a long-acting memory T cell response, andhas an excellent prevention effect on tumors.