Bacteriocins produced by lactic acid bacteria (LAB) are ribosomally synthesiszed polypeptides or proteins with antibacterial activity. LAB are generally recognized as safe bacteria, and the bacteriocins produced by LAB are well known. Therefore, they have drawn widely attention on their applications. However, the limited understanding of mechanisms of bacteriocins from LAB, to some extent, inhibits their effective development and applications. In this literature review, the related research progress about bacteriocins from LAB was summarized, the existing bacteriocins were systematically classified, and the mechanisms to against Gram-positive bacteria according to their classification were subsequently elaborated in this article. In the end, the potential applications of bacteriocins in aquaculture and aquatic product processing were discussed, aiming to provide new antimicrobial explorations and basic knowledge for the development and applications of bacteriocins from LAB.