The changes in the physicochemical properties， the diversity of microorganisms and the structure of microbial community in the soil planted continuously with flue-cured tobaccos of different planting years including continuous cropping for 0 year （CK）， continuous cropping for 2 years （T1）， continuous cropping for 4 years （T2）， continuous cropping for 6 years （T3）， and continuous cropping for 8 years （T4） in Hanzhong area of Shaanxi Province were analyzed to study the key factors affecting the obstacles for continuous cropping of flue-cured tobacco and its patterns. The results showed that the organic matter， pH， and the content of total carbon in soil decreased with the increasing years of planting. The organic matter， pH， and the content of total carbon in the soil of T4 was 8.34%， 25.39%， and 25.20% lower than that of CK. The diversity and abundance of bacteria and fungi in soil showed a trend of increasing first and then decreasing， with the dominant bacterial phyla being Actinobacteriota， Proteobacteria， Acidobacteriota， Chloroflexi and Firmicutes. The dominant fungal phyla were Ascomycota， Basidiomycota， and Mucoromycota. Compared with CK， the relative abundance of microorganisms under T3 changed significantly， with change in Actinobacteria， Firmicutes， and Basidiomycota of 4.04%， 6.24%， and 28.86%， respectively. It is indicated that continuous cropping of flue-cured tobaccos reduces the content of organic matter， pH， and the content of total carbon in soil， affecting the composition of microbial community in soil.