This study investigated methane productions and the microbial communities in the batch anaerobic digestion process with the mono-digestion of corn stalk (CS) and pig manure (PM), and the co-digestion of them. Co-digestion showed the best methane performance, the cumulative methane yield, 256.57 mL.gVS(-1); methane production potential, 281.55 mL.gVS(-1); maximum methane production rate, 10.17 mL.d(-1).gVS(-1); and lag phase, 4.24 d. Moreover, co-digestion achieved a more suitable microenvironment including pH, FA and FVFA compared to mono-digestions. Results of high-throughput sequencing indicated that in co-digestion the dynamic changes of relative abundances of phyla and predominant genera were very small and community structure presented a stable status. Acetoclastic pathway was the main biochemical pathway of methanogenesis in co-digestion and mono-digestion of PM, and the growth rate of Methanosaeta in co-digestion was higher. So suitable microenvironment in co-digestion resulted in high growth rate of methanogens and stable microbial community, and leaded to the high methane production. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.