Cellulose is one of the most important renewable resources in nature. In this paper, a strain j-n3 was isolated from the soil of corn field. The isolated medium with carboxymethyl cellulose as the sole carbon source and Congo red staining method were used for preliminary screening, and then the screened strains were cultured by liquid fermentation and enzyme activity was determined. Combined with morphological characteristics and molecular biological identification, strain j-n3 was identified as Bacillus.According to the preliminary study of enzymatic properties, the optimum pH of the enzyme is 6.0, and the optimum reaction temperature is 50℃. After treated with strain J-N3 for 20 days, the weight loss rate and cellulose decomposition rate of corn stalks reached 26.22% and 31.01%, respectively.