Abstract: In the context of excessive and inappropriate use of antibiotics, problems such as increased antibiotic resistance of bacteria and the deterioration of ecological environment are becoming increasingly serious. Antimicrobial peptides（AMPs） have been widely studied because of their broadspectrum antibacterial activity and membrane-lytic antibacterial mechanism which is not easy to produce drug resistance. As the only Cathelicidins family AMP in humans, LL-37 has various functions such as antibacterial, antifungal, antiviral, antibiofilm and immune regulation, which can effectively prevent inflammation and resist pathogen infections. Here, the expression and biological functions of LL-37 were described. The obstacles in the process of industrialization and molecular modification strategies were also sorted out. The content obtained here could provide novel ideas for the clinical application of new drugs, the creation of non-nutritious feed additives, and the development of surface preservatives based on LL-37.