Abstract: In order to explore the remediation effect of different bacterial agents on black and odorous water bodies, and reveal the changing law of microbial communities during the research process, different formulations of bacterial agents were used to restore black and odorous water bodies, and the effects of different bacterial agents on overlying water, sediment and microorganisms were discussed. The results showed that the pH of the overlying water in the bacterial agent group was slightly higher than that before the experiment. DO concentration in the overlying water of the chemical-composite microbial agent group was slightly lower than that of the blank group (6.95 mg/L), and the removal rates of NH₄ ⁺-N and TP in the overlying water reached 86.60% and 66.07%, while the removal rates of volatile sulfur (AVS) and organic matter in the sediment reached 79.20% and 52.71%, respectively. The removal effects were significantly better than other experimental groups. High-throughput sequencing showed that nitrifying bacteria、denitrifying bacteria and organic matter degrading bacteria in the sediment of the microbial inoculum group had high relative abundance, and the relative abundance of a genus under Vicinamibacterales in the chemical-compound microbial inoculum group was significantly higher than that in other experimental groups (1.07%-2.18%). The results of this study indicate that the chemical composite microbial agent has a good remediation effect on black and odorous water bodies.