Anaerobic digestion (AD) is an important method to dispose agricultural waste in the process of green agriculture development in China. It not only solve the problem of fuel shortages in rural areas, but also realize the harmless treatment and multi-level resource utilization of waste. Based on the total solids (TS) content of the feedstock, AD has been developed as liquid anaerobic digestion (TS＜15%) and solid-state anaerobic digestion (TS≥15%) technologies. In this paper, the gas production performance and micro-ecological succession law of corn straw in liquid and solid biogas fermentation were compared. The result showed that: The peak period of SS-AD biogas production was about 4 days later than that of L-AD, and the CH4 volume fraction of the SS-AD was lower than that of the L-AD in stable biogas production period. The biogas production rate of TS and methane conversion rate in SS-AD system were slightly lower than that of L-AD. After the fermentation, the contents of N, P and C in the SS-AD biogas slurry were lower than that of the L-AD. Acetic acid is the main component of VFAs in the two digestion systems, accounting for more than 70% of the total VFAs. High-throughput sequencing results showed that the bacteria in the two disgestion systems were mainly composed of Bacteroidetes, Firmicutes, Proteobacteria, Cloacimonetes, Synergistetes and Verrucomicrobia, which accounted for more than 80% of the total number of clones. Bacteroidetes is the largest class of bacteria, and its relative abundance is stable throughout the digestive stage, but the relative abundances of Proteobacteria and Firmicutes were decreased gradually after the start of fermentation, and eventually stabilized around 10%. The relative abundance of Cloacimonetes increases with digestion time, and the maximum value can reach 20.1% in SS-AD systems. The sum of the relative abundances of Verrucomicrobia and Synergistetes increases with the anaerobic digestion process. Methanosaeta, Methanospirillum, Methanocorpusculum and Methanoculleus are the dominant archaea in the two fermentation systems. These four types of archaea accounted for 24.4%-39.6% of the total number of clones in SS-AD system and 27.9%-48.0% in L-AD system. With the progress of the digestion, the archaea community showed a trend of transition from acetic acid nutrition to hydrogen nutrition. After fermentation, the proportion of these two types of archaea in the community wasin balance. The results of cluster analysis on microbial diversity showed that the difference between the bacteria and archaea community structure of the two systems gradually became obvious after the 4th and 8th day of fermentation. Further analysis showed that the main environmental factor affecting the L-AD micro-ecological structure of corn straw is acetic acid, and the hydrolysis of straw cellulose may be the key process to limit the conversion rate of raw materials. Phosphorus is the most important environmental factor affecting the micro-ecological structure of SS-AD systems, and how to increase the biomass of methanogenic archaea is the key to raise the biogas production rate of raw materials. The results of this study provide a scientific basis for regulating the anaerobic digestion process of corn straw and improving its bio-degradation efficiency. [ABSTRACT FROM AUTHOR]