Abstract: 【Objective】 To clarify the microbial diversity of sweet sorghum silage in the hope of providing a theoretical basis for silage production and storage. 【Methods】 In this study, the microbial diversity of silage from two varieties with or without the addition of silage additives were analyzed using high-throughput sequencing. 【Results】 The dominant bacterial phyla in sweet sorghum silage were Firmicutes, Proteobacteria, Bacteroidetes, Cyanobacteria and Acidobacteria, and the dominant bacterial genera were Lactobacillus, Enterobacter, Lactococcus and Corynebacterium. Ascomycota was the dominant phylum in fungal community. 【Conclusion】 The microbial flora composition of sweet sorghum silage is similar among different treatments, but the relative abundance is significantly different. Silage microbial agent reduces the relative abundance of microbial flora in sweet sorghum silage.