Soil degradation caused by successive planting is an important obstacle for the primary productivity of Chinese fir. However, the inhibitory effect of soil on pathogens determines whether plants can effectively resist the invasion of pathogens, which is an important performance of soil health in plantation. In our study, the first generation, the second generation, the third generation Chinese fir plantation and the natural secondary forest soil were selected, and the inhibition of soil bacterial communities from different generations on Fusarium oxysporum and Rhizoctonia solani was analyzed using invert and antagonism assays. The ecological process of soil bacterial community involving in pathogens suppression was studied by high-throughput sequencing. The results indicated that soil phosphorus showed a significant accumulation, while soil pH and soil organic matter (SOM) decreased with the increase of successive planting generations. However, the declined indicators were not significantly different between the third generation forest and natural forest. The successive planting of Chinese fir plantation significantly decreased the inhibitory effect of soil microbial community on pathogens, while the effect of natural secondary forest was significantly higher compared with plantations. The successive planting of Chinese fir significantly changed the composition of soil bacterial community, but no effect on α-diversity of the community, indicating high sensitivity of some key microbiota to successive planting. Random forest model further revealed that the lower abundance of some key microbes caused by Chinese fir successive planting was the main reason for the decline of soil pathogens suppression, and these microbes were mainly regulated by soil pH, SOM and total phosphorus (TP). Therefore, the long-term successive planting of Chinese fir would lead to the imbalance of soil microenvironment, and the reduced ability to inhibit pathogens, which is not conducive to improving productivity and sustainable management of plantations.