Abstract: In order to improve the control system of intelligent biogas digester in support of its operation theory, the crude fiber content, pH, microbial diversity and biogas production rate of biogas sludge were analyzed to understand their correlations.The result showed that the crude fiber content, pH and microbial diversity from various layers of biogas sludge performed no significant differences at same fermentation time in the first.Secondly, the crude fiber content, pH and microbial diversity from same layer exhibited significant changes along with fermentation time.Thirdly, in dynamic change of biogas production, the highest rate was detected in fermentation during 6hrs to 16 hrs with 1.12m3·m-3·d-1, followed by gradually depressing in production rate until the 72 hrs of the duration.In addition, the biogas production rate was significantly negative correlation with the content of crude fiber in biogas sludge but positive correlation with the pH, diversity index and homogeneous degrees index.