Abstract: To study the variations of bacterial community diversity and structure of cigar tobacco during industrial fermentation, samples of cigar filler tobacco were collected during a bulk blended fermentation process, and the Illumina MiSeq high-throughput sequencing technology was used to analyze the bacterial community diversity and structure. The results showed that during the fermentation of cigar tobacco, 1) the number of OTUs and species richness of the bacterial community after the blended fermentation decreased compared with those before the blended fermentation, while the species diversity increased; 2) the dominant bacterial phyla changed from Firmicutes to Proteobacteria, and the dominant bacterial genera changed from Oceanobacillus, Comamonas, and Bacillus to Comamonas, Sphingobacterium, Georgenia and Paenibacillus; 3) the 10 bacterial genera with significantly increased average relative abundance were Sphingobacterium, Georgenia, Paenibacillus, Parapusillimonas, Pseudomonas, DSSF69, Lysobacter, Pseudoxanthomonas, Brevibacillus and Pusillimonas, in which Sphingobacterium, Georgenia and Paenibacillus were the dominant genera after the blended fermentation. The seven bacterial genera with significantly decreased average relative abundances were Terribacillus, Klebsiella, Atopococcus, Corynebacterium, unclassified_f_Carnobacteriaceae, Aerococcus and Atopostipes. In conclusion, the bacterial community diversity of cigar tobacco increased during the industrial fermentation process, and the community structure changed significantly.