Abstract: Lignocellulosic biomass can be effectively digested in animal rumen, which makes rumen-derived anaerobic digestion as an attractive strategy. Based on the principles of bionics, this study designed an integrated two-phase anaerobic reactor, and investigated its hydrolysis acidification and methane-producing capability by feeding with straw, pig manure and river sediment as substrates. The results indicated that the biogas production rate in 1-9 d was fast and the increasing rate of cumulative gas production was 293.46 mL/（L·d）, the fastest biogas production rate in this period was 22.3 mL/（g_VS·d）, and the cumulative gas production was 0.13 L/g volatile solid. The pH value ranged from 7.3 to 8.2, and showed an overall opposite variation trend with the concentration of volatile fatty acids (VFAs), indicating that ammonia inhibition did not occur in the reactor. Soluble chemical oxygen demand (SCOD) produced by main reaction chamber was substantially utilized in secondary reaction chamber in 1-22 d, realizing the separation of hydrolysis process and the utilization process of hydrolysis products. In the reactor, Firmicutes and Bacteroidetes were the two most abundant bacterial phylums, and had hydrolysis and acid-production capacity. The reactor had not only the effects of substrate stratification and continuous absorption of VFAs, but also upper hydrolysis and acid production, and lower methane production. Therefore, the reactor can effectively prolong the solid residence time, improve the hydrolysis and acidification efficiencies, and eliminate partial acid inhibition in the reactor.