Abstract: In order to study the sludge microbial community structure under the IC anaerobic reactor and hydrolysis acidification tank process in the industrial wastewater treatment field, the 16S rDNA hypervariable region V3~V4 of anaerobic sludge from different processes were analyzed by employing the Illumina MiSeq platform. The dominant bacteria group in the sludge of the hydrolysis acidification tank is the Proteobacteria, and the main dominant bacteria in the granular sludge of the IC reactor are Bacteroidetes and Firmicutes. The proportion of Proteobacteria is greatly reduced. It is speculated that pathogenic bacteria will be greatly reduced in the process of anaerobic treatment of wastewater, and the IC reactor has a significant microbial purification effect on the water quality. In addition, a certain proportion of Archaea appears in the sludge of the IC reactor, and methanogens are more active, and a specific bacterial microbial community structure is formed during operation. The proportion is relatively stable, which is conducive to the reaction. Results presented in this manuscript provide theoretical guidance on the rapid construction and optimization of microorganisms in the anaerobic methane production system for treating fur wastewater in the IC reactor.