In the process of traditional fermentation， abundant nutrients， open fermentation environment and traditional fermentation technology contributed to diverse and relatively stable microbial community ecosystem. Their growth， metabolism and interaction control the fermentation process and produce rich nutrients and unique flavor substances， which are the essence of traditional fermentation technology. There are many types of microbial interactions， including mutualism， favoritism and competition between fungi and fungi， fungi and bacteria， bacteria and bacteria， respectively. In recent years， with the wide application of high-throughput DNA sequencing technology and omics-based analytic technology， the understanding of microbial interactions in traditional fermentation processes has further deepened. This review summarized the microbial community structure from different traditional fermented foods and the state-of-the-art knowledge of microbial interactions in these fermentation processes， and especially focused on the molecular mechanism in typical microbial interactions.