Polymerase Chain Reaction- Denaturing Gradient Gel Electrophoresis (PCR-DGGE), DNA-sequencing, and Principal Component Analysis (PCA) technologies were adopted to assess the soil microbial community structure changes during the evolution of Cunninghamia lanceolata plantation soil quality. The relationship between soil microbial community structure and soil quality changes was analyzed from C. Lanceolata plantations with different soil qualities at the Huitong Experimental Station of Forest Ecology, CAS. The dominant species of soil bacteria in the C. Lanceolata plantations in this region are α, β, γ-proteobacteria, and Cytophaga Flexibacter Bacterioides (CFB). The dominant species of fungi are the Ascomycetes and Basidiomycetes subphylum species. The Shannon index showed that bacterial diversity associated with monospecific C. lanceolata plantations was lower than that of the natural forest or mixed C. lanceolata plantations. With continuous planting of artificial fir, the index continues to decrease. The replacement of natural forest with artificial fir also affects microbial species composition. For example, bacteria species with a close phylogenetic relationship to Pedobacter cryoconitis disappear from the artificial fir plantation soil. However, bacteria species with a close phylogenetic relationship to Xanthomonas sp. and Rhodanobacter sp. begin to appear in the soil of the continuously planted artificial fir forest. The pattern of change in the fungi community structure is opposite to that in the bacteria community. When the artificial fir forest replaces the natural forest, artificial fir is continuously planted, and the soil fungi diversification index continues to increase. The fungi community structure varies significantly between the third generation of artificial fir forest and the natural forest. Some fungi became dominant in the third generation of artificial fir forest, including Sclerotinia sclerotiorum, Mycosphaerella cannabis and Marasmius graminum. Other research has shown that S. sclerotiorum and M. cannabis can cause a variety of plant diseases, and M. graminum is a litter decomposition bacterium. The dominant fungi species originally existing in the natural forest soil disappear from the third generation artificial fir forest soil. The soil bacteria and fungi community structures of the mixed C. lanceolata-Michelia macclurei and C. lanceolata-Alnus cremastogyne plantations are similar to the dominant edaphon species in the natural forest. This study evaluated the relationship between soil quality evolution and changes in microbial communities and functional groups by correlation analysis. The soil bacteria diversification index has a positive correlation with the total organic carbon (TOC), total nitrogen (TN), extracted Carbon (C_ext), ammoniacal nitrogen (NH₄⁺-N), available potassium, available phosphorus and pH of the soil. The fungi diversification index change is positively correlated with the C:N ratio in the soil but negatively correlated with the pH. These findings suggest that different silvicultural practices have significant impacts on the soil microbial community through influences on soil chemical properties. There were significant correlations between soil quality evolution and changes in dominant soil microorganism species and soil quality change is related to the dominant species changes in soil bacteria and fungi. For example, Burkholderia sp. and Pedobacter sp. can dissolve phosphorus and potassium and the pathogenic bacteria Xanthomonas sp., and pathogenic fungi S. sclerotiorum and M. cannabis can cause plant diseases. The dominance of these species changes with soil quality evolution from natural forest to artificial fir plantations.