Abstract: In order to investigate the structure and diversity of soil bacterial community in 0-60 cm soil layers under rice-crayfish integrated system, the characteristics of soil bacterial community in paddy field were examined to provide theoretical basis for studying soil nutrient cycling in paddy field under this system. Soil samples in the soil layers of 0~10 cm, 10~20 cm, 20~30 cm, 30~40 cm, 40~50 cm and 50~60 cm were collected at a 15-year continuous location experiment in Bailuhu Farm of Qianjiang City of Hubei Province. The structure and diversity of soil bacterial community were analyzed by high-throughput sequencing technique, and the relationship between soil bacterial community characteristics and soil physicochemical properties was studied. The results showed that compared with the mid-season rice monoculture system, the long-term integrated rice-crayfish system significantly increased the contents of soil organic carbon, total nitrogen, total phosphorus and available potassium in the soil layers of 0~10 cm and 20~40 cm, 0~30 cm, 0~20 cm and 30~40 cm, and 10~40 cm, respectively. The long-term rice-crayfish integrated system changed the community composition of soil bacteria, significantly increasing the relative abundance of Chloroflexi, Bacteroidetes, Nitrospirae and Gemmatimonadetes, and decreasing that of Cyanobacteria, Actinobacteria and Verrucomicrobia. The long-term rice-crayfish integrated system significantly increased the species richness and diversity of bacteria in 10~20 cm and 30~50 cm soil layers, and decreased the richness of bacteria in 0~10 cm soil layers. The correlation analysis showed that organic carbon, total nitrogen, available phosphorus and available potassium were the main factors affecting the bacterial community structure and diversity in the rice-crayfish integrated system. In general, the long-term rice-crayfish integrated system changed the physical and chemical properties of paddy soil and the composition of soil bacterial community, and improved the richness and diversity of bacterial species in deep soil.