Traditional fermented soybean foods including dajiang, douchi, sufu and soy sauce are considered as indispensable to people’s dietary structure in China due to its unique flavors and health benefits. The complex favor compounds in fermented soybean foods are reported closely related to the metabolisms of various microorganisms in fermentation systems. Thus, understanding the influences of complex microbiota on the formation of flavor components in traditional fermented soybean foods is important to the production of high quality fermented soybean products. In recent years, numerous researches have been conducted to investigate the microbial community and flavor metabolites during fermentation using high-throughput sequencing and mass spectrometry-based metabolomics analysis. While, there is no systematic review of microbiota and flavor characteristics of fermented soy products from China. This review comprehensively discusses the traditional fermentation processing, bacterial community and flavor characteristics of four traditional fermented soybean foods in China including dajiang, douchi, sufu, and soy sauce. Finally, it is proposed that emerging technologies such as metagenomics, transcriptomics, proteomics and metabolomics should be applied to further improve the accuracy of the analysis of microbial diversity and flavor components for accurately revealing the relationship between the microbial community and the formation of characteristic flavor in traditional fermented soybean products.