The invention discloses a lanthiopeptin precursor peptide amyA6 and a preparation method and application thereof, and relates to the technical field of biology. The amino acid sequence of the lanthiopeptin precursor peptide amyA6 is shown as SEQ ID NO: 1. The lanthiopeptin precursor peptide amyA6 is added in a bacillus amyloliquefaciens fermentation process, so that the antibacterial activity of bacillus amyloliquefaciens metabolite can be remarkably improved, and the antibacterial activity lasting time is 4 times or above of the original antibacterial activity lasting time.