Abstract: Succession of microbial community structure in traditional fermented foods is complicated, and the metabolism pathways of flavor compounds are various during fermentation. As the “soul” of fermented foods, microorganisms influence the sensory, nutrition and functional characteristics of the fermented foods through a variety of metabolism pathways, which are closely related to the formation of flavor. Revealing the relationship between microorganism and flavor compounds is advantageous to identify the potential flavor-forming microorganism and regulate flavor characteristics of fermented foods. In this paper, the relationship between microorganism diversity and flavor development in the typical traditional fermented foods, including liquor, fermented vinegar, fermented vegetables and fermented animal products is mainly reviewed, and the flavor metabolism mechanisms of core microorganisms are briefly discussed. This review will provide some references for the quality improvement of traditional fermented foods.