Abstract: In order to reveal the soil bacterial community structure characteristics in healthy and tobacco bacterial wilt-susceptible soils, Illumina-MiSeq high-throughput sequencing technology was used to analyze the bacterial 16S rRNA gene sequences. To study the bacterial community structure and biomarker species of healthy and tobacco bacterial wilt-susceptible soils in dryland and paddy field, and to investigate the incidence of bacterial wilt in tobacco field and the abundance of R.solanacearum in soil. The results showed that the incidence of bacterial wilt in susceptible tobacco fields was significantly higher than that in healthy tobacco fields, and there was no significant difference between dryland and paddy field. The number of R.solanacearum in susceptible soil was significantly higher than that in healthy soil, with an increase of 10⁶-10⁸ times. There was no significant difference in bacterial species richness between susceptible and healthy soils, but the evenness of dryland healthy soil was significantly better than that of dryland susceptible soil. The significant difference of Beta diversity among groups showed that the bacterial Beta diversity of healthy soil was significantly higher than that of susceptible soil, and the bacterial diversity of dryland soil was significantly higher than that of paddy field. PCoA and NMDS ordination showed that there were significant differences in bacterial community structure between susceptible and healthy soils. LEfSe analysis showed that Flavobacterium, Bradyrhizoum and Rhodanobacter are the biomarker bacteria in tobacco soil susceptible to tobacco bacterial wilt. unidentified_Burkholderiaceae is the biomarker bacteria of healthy tobacco soil. Sphingomonas and Acidibacter were enriched in dryland susceptible soil. Unidentified_Acidobacteria was enriched in dryland healthy soil. Thiobacillus and Defluviicoccus were enriched in susceptible soil of paddy field. Gemmatimonas was enriched in healthy soil of paddy field. In conclusion, the change of bacterial community structure and the difference of the bacterial biomarker species in the soil of tobacco field are the important characteristics of the occurrence of tobacco bacterial wilt. The research could provide scientific basis for the prevention and ecological control of tobacco bacterial wilt.