Disclosed is an antimicrobial peptide having an amino acid sequence of formula presented as (P1)M(A1X1X2)N(P2)X, wherein Pi is selected from the group consisting of basic amino acids including Arg and Lys； A1 is selected from the group consisting of aromatic amino acids including Trp, Phe and Ala； X1 is selected from the group consisting of basic amino acids or nonpolar amino acids, including Arg, Lys, VaI, Leu, Ala and Ile； X2 is selected from the group consisting of basic amino acids or nonpolar amino acids, including Arg, Lys, VaI, Leu, Ala and Ile； P2 is selected from the group consisting of basic amino acids including Arg and Lys； and the numbers of M and X are respectively 0~2； when N>；2, A1 is Ala and the Ala residues are less than N-2.
