Abstract: In order to improve the acidification efficiency of rice straw in biogas production, provide cheap nitrogen source for the growth of high-temperature composite strains WSC-6, and reduce operating costs, biological pretreatment of rice straw was carried out by high-temperature composite strains WSC-6 and using untreated rice straw as carbon source and fresh swine manure or dried swine manure as nitrogen source. The result indicated that nitrogen source in fresh swine manure could be sufficiently utilized by high-temperature composite strains WSC-6, and the utilization rate of total nitrogen reached to 81.5%. The degradation rate of rice straw in fresh swine manure was also higher than that in dried swine manure, and total degradation rate of rice straw in fresh swine manure was 48.3%, and degradation rate of cellulose, hemicellulose and lignin was 67.3%、79.3% and 27.9%, respectively. In biological pretreatment process of rice straw, whether fresh swine manure or dried swine manure as nitrogen source, the reaction would not produce acidification with pH values ranging from 6.5 to 8.2. Fresh swine manure as nitrogen source both reduced biological pretreatment costs of rice straw, and eliminated the environmental pollution, which is important to improve the biogas industrialization production.