Plant litter plays a pivotal role in the formation of soil organic matter, with its decomposition rate closely associated with the soil habitat at local scale. The pace of litter decomposition varies across different soils, consequently influencing soil carbon turnover and nutrient utilization efficiency. The microbial communities closely associated with leaf litter decomposition primarily originate from the leaf detritusphere. These microbial communities play a crucial role in the soil nutrient cycling and the decomposition of organic matter. However, current research on the dynamic changes in microbial communities within the leaf detritusphere is relatively limited. This research focused on the leaf litter of Alternanthera philoxeroides, examining the dynamic changes in the bacterial communities of the leaf detritusphere across different soils (Histosols, Ferralosols, and Alluvial soil) and decomposition stages (30%, 60%, and 90%) through high-throughput sequencing. The results indicated that as decomposition progressed, the diversity of bacterial communities in the leaf detritusphere gradually increased, and higher levels of community diversity (Alpha diversity: Histosols > Alluvial soil > Ferralosols) correlated with faster decomposition rates (k: Histosols > Alluvial soil > Ferralosols). The study further revealed that changes in the composition of bacterial communities in the leaf detritusphere were significantly affected by both soil type and decomposition stage, with the former exerting a greater influence (P < 0.001). Specifically, the dominant bacteria in the leaf detritusphere varied with soil, with Proteobacteria leading in both Histosols and Alluvial soil (55.33% and 53.10%, respectively), while Actinobacteriota predominated in Ferralosols (63.95%). Influenced by the decomposition stage, the average relative abundance of each dominant phylum within the leaf detritusphere across different soils decreased in the later stages of decomposition. Conversely, oligotrophic taxa, represented by Chloroflexi, significantly increased in the later stages of decomposition (P < 0.05), with increases ranging from 5.66 to 413.80 times compared to the early stages of decomposition. Moreover, in various soils, the assembly of bacterial communities in the leaf detritusphere was influenced by deterministic processes, with the complexity of their co-occurrence networks decreasing in the order of Alluvial soil, Histosols, Ferralosols. Proteobacteria and Actinobacteriota played key roles in the construction and maintenance of the entire leaf detritusphere bacterial community. This study reveals how different soils regulate the composition and diversity of bacterial communities in the leaf detritusphere, thereby influencing the decomposition process of litter.It provides data support for a deeper understanding of the key role played by bacterial communities in the leaf detritusphere in the nutrient cycling process of ecosystems.