This study addresses the critical production issue of long-term monoculture causing microecological imbalance and yield and quality decline in fluecured tobacco soils, aiming to explore the regulatory mechanism of reduced nitrogen fertilization combined with biochar application on the soil microbial community structure of consecutive tobacco fields. The study conducted using the flue-cured tobacco variety Longyan 101 as the research object. A field plot experiment was conducted in situ in a continuously cropped tobacco field. Treatments included two nitrogen application levels: conventional nitrogen application(0.03 t/hm2)and reduced nitrogen application(0.015 t/hm2),each combined with different rates of biochar application(0,10,and 20 t/hm2). The objective was to evaluate their regulatory effects on the soil microbial community structure in the continuous cropping system. The results showed that there was no significant difference in the yield of flue-cured tobacco under different levels of biochar when reducing nitrogen application and conventional nitrogen. No significant difference was observed in the microbial α diversity of tobaccos among different biochar treatments under conventional nitrogen level. However, the reduced nitrogen application treatment significantly improved the soil microbial community structure. The most pronounced effect was observed with the combination of reduced nitrogen and 10 t/hm2 biochar, which increased the OTU richness index by 17.9%compared to the treatment with conventional nitrogen combined with 10 t/hm2 biochar. This treatment also promoted the enrichment of microbial species including Rhizobacter, Curvibacter, Papulaspora, and Rhizoctonia, play a central role in maintaining microbial community stability and ecological functions. Considering soil health for flue-cured tobacco cultivation, the combination of reduced nitrogen application with 10 t/hm2 biochar proved to be the most effective approach, demonstrating significant improvements in long-term continuously cropped tobacco fields.