The aimed to explore cellulose-degrading bacterial strains from sheep manure composting to enrich the microbial resources of functional inoculants for sheep manure composting. According to the temperature changes during the composting process of sheep manure，it was divided into different stages，and samples were collected from each stage. The dominant microbial community was analyzed by 16S rRNA sequencing. Strains with cellulose degradation ability were separated and screened. The optimal strain was selected for strain identification and the enzyme production conditions were optimized. The composting validation experiment was conducted，and the actual effects were evaluated. The results showed that the aerobic composting process of sheep manure was divided into three stages:initial phase(T1，Day 0)，thermophilic phase(T2，Days 1-12) and cooling phase(T3，Days 13-35). 16S rRNA sequencing revealed significant shifts in the relative abundances of six dominant phyla(Proteobacteria，Bacteroidetes，Firmicutes，Actinobacteria，Deinococcus-Thermus and Gemmatimonadetes) across these stages. Notably，Proteobacteria and Firmicutes exhibited marked enrichment during the T2 phase compared to T1 and T3 phase. Thirty cellulose-degrading strains were isolated，with 11 demonstrating superior activity. Strain G11，isolated from T2 phase，identified as Acinetobacter john sonin showed the highest carboxymethylcellulase(CMC)activity(33.67±0.94)U/mL under optimized conditions(37℃，1% inoculum，pH 8，48 h cultivation)，representing a 22.4% improvement over the basal medium. Compost validation trials confirmed that supplementing the existing inoculant with strain G11 increased peak cellulase activity to 94.49 U/g，and enhanced laccase activity synergistically. The results highlighted the potential of strain G11 as a high-efficiency cellulose-degrading agent for accelerating sheep manure composting. This study provided a theoretical basis for developing multifunctional microbial inoculants in agricultural waste management.