Abstract: In this paper,COMSOL is used to calculate and analyze three influencing factors of microwave pyrolysis. The results show thatthe maximum difference in average temperature is more than 50%,and the maximum microwave energy absorption efficiency is 92% under the calculation conditions. Adding akindoftypical absorbent agentcarbon spheres can improve the energy absorption efficiency of biomass,resulting in the average temperature of biomassincreasing,and the energy efficiency can be increased by 5% at most. The temperature uniformity of biomass can be optimized by adding rotation speed,the maximum temperature standard deviation difference between with and without rotation speed is about 26%. However,the rotation speed has little effect on the temperature uniformity.