Abstract: To study the effects of different potassium sulfate dosages on the bacterial community diversity of tobacco planting soils, soil bacterial community diversity was analyzed by consecutive field experiment for 8 years. High-throughput sequencing of the 16S rRNA V3-V4 region of each treated tobacco planting soil was carried out, and α diversity index, community species composition and abundance information of the bacterial communities were obtained. The community composition and abundance were analyzed by PCA cluster analysis and UPGMA cluster analysis. The correlations between the top ten dominant bacteria and soil pH, soil enzyme activity, potassium and sulfur content were analyzed. The results showed that: (1) Compared with the natural vegetation, the amount of bacteria of CK was reduced. In the fertilization treatments, the abundance, diversity and uniformity of the bacterial community increased significantly when the input of K₂O was 247.57 kg/ha, and the input of S was 125.4 kg/ha. (2) Proteobacteria, Acidobacteria and Actinobacteria were the dominant bacteria in all treated planting soils of this experiment, and with the increase of potassium sulfate application, the relative content of the Acidobacteria was significantly reduced, while Proteobacteria and Actinobacteria increased in different degrees. (3) The results of bacterial community similarity analysis for each treatment showed that long-term application of potassium sulfate could significantly change the soil bacterial community composition. (4) Correlation analysis showed that soil pH, soil sucrase activity and urease activities, the content of potassium and sulfur played an important role in the abundance, diversity and relative abundance of soil bacterial communities in the region.