Aiming at the problem that the direct return of straw to the field in the farmland ecosystem leads to the increase of greenhouse gases(CO₂，CH4，N2O)，under the mode of rice-wheat rotation and straw returning to field，the additional microbial straw decomposition characteristics of the decay bacteria in the consumption and decomposition of straw was considered，which could significantly change the C/N of straw and the life activity of the microorganism of the farmland and the characteristics of the nitration reaction，and the effect of this measure on the carbon sequestration and emission reduction was investigated. Three treatments were set up，including straw returning with liquid microbial agent(LM+ST)，straw returning with powder microbial agent(PM+ST)and straw returning without microbial agent(CK+ST). The experimental results showed that LM+ST and PM+ST reduced greenhouse gas emissions to a certain extent，but in the rice and wheat season，there were great differences between different types of gas. Compared with CK+ST，the CO₂，CH4，N2O average emissions of LM+ST and PM+ST treatments were lower by 31.7%，36.9%，39.2% and 12.0%，20.6%，29.2%，respectively. This study can provide reference for the study of solid carbon emission reduction of straw mulch in no tillage mode.