This application relates to an useful drug for prevention or treatment of avian influenza virus infection, and specifically provides a multiple antigen peptide comprising a dendritic core and 4-8 antigen peptides, wherein each of the antigen peptides is bound to a terminus of the dendritic core directly or through a spacer, and is a peptide consisting of 7-12 consecutive amino acids in the amino acid sequence of SEQ ID NO: 4, the multiple antigen peptide inducing the production of IgG antibodies in mammalian animals or birds, and further provides an immunity inducer comprising the multiple antigen peptide.