Abstract: The dynamic change of fermented grains' alcohol, residual sugar, residual starch, total acids and total esters and microbial communities in the fermentation process of multi-grain of the flavor liquor cavities were analyzed in this paper.The result showed that the main fermentation period of multi-grain and flavor fermentation completed within 30d in the fermentation.During this period, the maximum alcohol reached 6.47° in the saccharification of yeast and mold.At the same time, the residual sugar declined rapidlly and the residue amylin resolved swiftly.After 30d, there was no yeast surviving in lower Grains.The organic acids and esters increased rapidlly in the role of facultative anaerobic bacteria and anaerobic bacteria.In the fermentation stage, filamentous fungi and bacteria appeared peak 2 and 3 times respectively.The result of the analytical and flavor liquor cavities fermentation process had important reference value.