In order to explore the influences of intercropping sweet potato on rhizosphere soil nutrients，enzyme activities，and microbial communities of flue-cured tobacco，flue-cured tobacco(Var. LY1306)and sweet potato(Var. Pushu32)were used as experimental materials，a controlled pot experiment simulating field planting was conducted，and high-throughput sequencing technology was applied to study the effects of planting patterns(M:monoculture tobacco；I:intercropping of tobacco and sweet potato)and nitrogen application levels(N1:no nitrogen application；N2:normal application of nitrogen fertilizer，N 0.80 g/pot)on the diversity，community composition and community structure of bacteria and fungi in the tobacco rhizosphere soil，and the relationships between soil microbial diversity，dominant phyla，and environmental factors were analyzed by combining soil available nutrient contents and nitrogen metabolizing enzyme activities. The results showed:(1)Compared with tobacco monoculture，intercropping sweet potato increased the content of available nutrients，the activities of nitrogen metabolism enzymes，and the richness and diversity of soil bacterial and fungal communities in tobacco rhizosphere，and the effect of N2I treatment was the highest.(2)In terms of microbial community composition，the dominant bacterial phyla of tobacco rhizosphere soil were Firmicutes，Actinobacteriota，Proteobacteria and Chloroflexi. The dominant phylum of fungi was Ascomycota. Regardless of whether nitrogen fertilizer was applied or not，compared to tobacco monoculture，intercropping sweet potato increased the average relative abundance of Chlorobacteria and Acidobacteriota in tobacco rhizosphere soil，and reduced the average relative abundance of Firmicutes，Proteobacteria，Bacteroidota，Ascomycota and Basidiomycota.(3)Correlation analysis showed that the contents of soil alkaline hydrolyzable nitrogen，available phosphorus，available potassium and the activities of protease and urease affected the alpha diversity and dominant phyla composition of bacteria and fungi in the rhizosphere soil of tobacco. LEfSe analysis showed that the main dominant bacteria under N2I treatment were Actinobacteriota，Acidobacteriota，and Streptomycetaceae，while the main dominant fungi were Microascales and Mortierellaceae.(4)PCoA analysis showed that intercropping sweet potato and applying nitrogen fertilizer had a certain impact on the community structure of bacteria and fungi in the rhizosphere soil of flue-cured tobacco，but nitrogen fertilizer application had more significant effects on the community structure of bacteria and fungi than planting patterns，and there were significant differences in the soil bacterial and fungal community structure under N2I treatment compared to other treatments. In summary，intercropping sweet potato could increase soil fertility，microbial diversity and richness of tobacco rhizosphere，improve soil microbial community composition and structure，and thus facilitate the improvement of soil microenvironment in tobacco rhizosphere.