In order to explore the application effect of cellulose-degrading bacteria in compost decomposing，the experiment mixed the carcasses of livestock and poultry with straw after high temperature treatment，and divided them into the control group without adding bacterial agent and adding 1% high temperature resistant cellulose bacteria （Parageobacillus thermoglucosidasius）.The compost was composted by aerobic static ventilation for 28 days，and the physical and chemical parameters （temperature，pH，moisture content，ammonium nitrogen，nitrate nitrogen，nitrite nitrogen，total carbon and total nitrogen）and nitrogen conversion function during the composting process were determined.The results showed that the ammonium nitrogen content and nitrate nitrogen content of the bacterial agent group were significantly higher （P<0.05） than the control group，but the final total nitrogen content of the bacterial agent group was lower than the control group.The copy number of nirK in the control group in the pre-composting period was significantly higher than that in the inoculum group （P<0.05）and was significantly positively correlated with the content of NH₄⁺ （P<0.05）； the copy number of nirS in the inoculum group was extremely significantly higher than that in the control group （P<0.01），and has a very significant positive correlation with NO₃^- content （P<0.01）.In the middle stage of composting，the copy number of narG in the control group was significantly higher than that in the inoculum group （P<0.01），and the correlation with NH₄⁺ content was close to the significant level （P=0.064）； in the late stage of composting，the copy number of nosZ in the control group was extremely significantly higher than bacterial agent group （P<0.01）.The high temperature-resistant cellulose-degrading bacteria mainly change the nitrogen cycle of the compost through ammonia oxidation and denitrification in the early stage of composting，but also promotes denitrification and increases nitrogen loss.