Antimicrobial peptides have been attracting increasing attention for their multiple beneficial effects. In present study, a novel AMP with a molecular weight of 1875.25 Da, was identified from the genome of Lactobacillus casei HZ1. The peptide, which was named as LHH1 was comprised of 16 amino acid residues, and its α-helix content was 95.34% when dissolved in 30 mM SDS. LHH1 exhibited a broad range of antimicrobial activities against gram-positive bacteria and fungus. It could effectively inhibit staphylococcus aureus with a minimum inhibitory concentration of 3.5 μM and showed a low hemolytic activity. The scanning electron microscope, confocal laser scanning microscope and flow cytometry results showed that LHH1 exerted its antibacterial activity by damaging the cell membrane of staphylococcus aureus. Meanwhile, LHH1 also exhibited anti-cancer activities against several cancer cells including MGC803, HCT116 and C666-1 cells, and one major action of its anti-cancer mechanism was breaking the cell membrane.