The invention discloses a method utilizing phage antibody library to screen human histamine receptor 4 (HR4) epitope mimic peptide and a vaccine construction method thereof. A phage random dodecapeptide library is utilized to screen one polypeptide section, and the amino acid sequence of the polypeptide section is FNKWMDCLSVTH. The provided method utilizes a phage random dodecapeptide library technology to screen the polypeptide sequence of HR4 epitope mimic peptide; ELISA identifies the affinity of phage monoclone on HR4 mono-antibody, then sequencing is carried out to obtain one polypeptide sequence, which is names as PT1; the targeting result of phage positive clone is further identified to indicate that phage positive clone can specifically combine the human HR4 monoclonal antibody; the human HR4 monoclonal antibody specific polypeptide can be obtained through screening; thus the HR4 epitope mimic peptide vaccine can be constructed; and the vaccine on the basis of HR4 mimic epitope can be used to treat allergic rhinitis in clinic, can also be applied to the research on HR4 antagonist, and provides primary experimental references for the construction of HR4 antagonist.