Abstract: Fermentation is an important means of fish preservation and processing. Fermentation gives fish unique flavor and texture, and microorganisms play an important role in the process of fermentation. This paper introduces the composition of microorganisms in fermented fish and its role in inhibiting miscellaneous bacteria, substance degradation, flavor formation and biogenic amine accumulation, in order to help understand the dominant microorganisms and their fermentation characteristics, prepare industrial starter and improve the yield and quality of fermented fish. In addition, the further study of fermented fish is prospected.