The present invention provides an antigen chimera, comprising: a fusion protein of an antigen and a mucosal immune adjuvant protein monomer capable of forming a multimer； and the mucosal immune adjuvant protein monomer capable of forming the multimer； wherein the mucosal immune adjuvant protein monomer capable of forming the multimer is one selected from cholera toxin B subunit (CTB) and E. coli heat-labile enterotoxin B subunit (LTB), the multimer is a pentamer, and in the chimera the molar ratio between the fusion protein and the mucosal immune adjuvant protein monomer capable of forming multimers is 1:4. In the present invention, a characteristic that a mucosal immune adjuvant protein can form a pentamer is used to form a chimeric structure, so as to form an antigen having a higher potency. Moreover, a mucosal immune adjuvant protein is used to improve an immune effect, so as to improve an effect of enhancing antigen immunogenicity. In addition, the chimeric protein antigen formed with the recombined antigen of the present invention stimulates a mucous membrane to produce secretory IgA and induce the occurrence of mucosal immunity.
