Soil bacteria can effectively promote energy flow and material circulation in soil, and the soil quality condition can be reflected by the composition, quantity, and diversity of bacterial communities. This study aimed to investigate the effects of different vegetation types on soil bacterial community structure and diversity, assisting us to completely understand soil quality condition and facilitate effective management and sustainable utilization of vegetation in the Xiaolongshan Mountain region. Soil was collected from Pinus tabulaeformis and Bupleurum chinense plantations at Xiaolongshan Mountain of Gansu Province. High-throughput sequencing technology was used to analyze the community structure and diversity of soil bacteria under the two different types of vegetation, and to analyze the effects of soil nutrient indices on soil bacterial community structure. The results showed that (1) The abundance and diversity of bacterial communities were not different between the two vegetation-type soils; however, the bacterial communities in P. tabulaeformis plantation soil had lower uniform degree than those in the B. chinense soil. (2) The ribosomal database project classifier revealed 37 phyla, 84 classes, and 168 orders of bacteria in the soil samples under the two types of vegetation. The dominant phyla were Proteobacteria, Acidobacteria, Chloroflexi, Planctomycetes, and Actinobacteria; Proteobacteria had lower abundance in the P. tabulaeformis soil than in the B. chinense soil (P < 0.05). Chloroflexi had higher relatively abundance in the P. tabulaeformis soil than in the B. chinense soil (P < 0.05), whereas the relative abundance of other dominant bacteria showed no difference between the two vegetation-type soils. At the class level, Acidobacteria, β-proteobacteria, Actinobacteria, and Gemmatimonadetes were the predominant bacterial communities, and their relative abundance showed no difference between the two vegetation-type soils. (3) The relative abundance of Proteobacteria was significantly negatively correlated with available nitrogen (P < 0.05), and the relative abundance of Acidobacteria was significantly negatively correlated with total nitrogen (P < 0.01). The results of redundancy analysis showed that available nitrogen and total nitrogen had the greatest impact on the soil bacterial community structure. These results suggest that the community composition and diversity of bacteria were similar in the two soils under different vegetations, but the species of bacterial communities in the P. tabulaeformis soil showed more centralized distribution than those in the B. chinense soil. In conclusion, Proteobacteria and Chloroflexi were the dominant phyla and showed significantly different distribution in the two vegetations, and available nitrogen and total nitrogen were the main factors affecting the soil bacterial community structure.