In 2018, five fertilization treatments were set up in Guiyang tobacco district, Chenzhou city, Hunan province: CK (conventional fertilizer), T1 (conventional + high carbon base fertilizer), T2 (conventional + high carbon base fertilizer + Bacillus subtilis), T3 (conventional + high carbon base fertilizer + Trichoderma harzianum), T4 (conventional + high carbon base fertilizer + Bacillus subtilis + Trichoderma harzianum). Soil total carbon, total nitrogen, available phosphorus, potassium and other chemical indicators were determined and high-throughput technology was used to analyze soil microbial diversity and community structure to explore the effects of high-carbon fertilizer combined with microbial agents on chemical properties and microbial community of tobacco-growing paddy soil. The results show that: 1) Compared with CK treatment, the soil total nitrogen content of T2, T3 and T4 treatments increased by 20%, 28% and 28% respectively, showing significant differences with CK treatment. Nitrate nitrogen content in soil treated with high carbon-based fertilizer increased by 48.70%, 49.90%, 89.18% and 111.72% respectively, which had significant difference with CK treatment. 2) Compared with CK treatment, the number of bacterial OTU decreased by 8.17%, 10.03%, 17.40% and 14.04% respectively, and there were significant differences in the number of bacterial OTU between T3, T4 and CK treatment. There were significant differences in bacterial Chao1 and ACE indices between T2 and T3, and significant differences in fungal Shannon and Simpson indices between T1 and T2. 3) Compared with CK treatment, T1 treatment with high carbon base fertilizer had no significant effect on the dominance and relative abundance of fungi. The relative abundance of Actinobacteria in T2 and T3 treatments were increased by 79.86% and 41.88%, respectively. The relative abundance of Nitrospirae was decreased by 29.31% in T3 treatment. The relative abundance of Chytridiomycota was increased by 107.31% in T2 treatment and the relative abundance of Basidiomycota increased by 86.86% in T4 treatment. There were significant differences between them and CK treatment. The effects of different treatments on soil microbial community structure were not stable, and the effects on bacteria and fungi were different. 4) The correlation analysis showed that there was a significant correlation between the content of total nitrogen, ammonium nitrogen and available potassium in the soil and the relative abundance of dominant soil microflora, which indicated that the change of soil chemical properties by high carbon base fertilizer affected the abundance of dominant soil microflora.