The application of biochar and organic fertilizer to soil,an important source of greenhouse gases,plays an important role in soil carbon nitrogen conversion and micro-gas metabolism,however few studies have focused on the soil microbial activity and soil greenhouse gas emissions influenced by the mixed application of biochar and organic fertilizers.This study adopts indoor culture experiment,using soil added biochar and biochar mixed with different organic fertilizers,to explore the effects of biochar and different organic fertilizers on soil greenhouse gas emission and soil microbial activity.Five treatments were set up in this experiment,that is,fresh soil(S),fresh soil + 2% biochar(SB),fresh soil + 2% biochar + 1% soybean cake(SBS),fresh soil + 2% biochar + 1% wheat straw(SBW),fresh soil + 2% biochar + 1% chicken manure(SBC).The results show that the effect of adding biochar alone to soil on greenhouse gas emission is not obvious;The application of mixed biochar and organic fertilizer can significantly increase the soil CO_2 and N_2O emissions,while the effect on CH_4 emission is not obvious;application of organic fertilizer presents a sizable contribution to the greenhouse effect according to the dynamics of global warming potential(GWP);the mixed application of biochar and organic fertilizer also can increase microbial biomass carbon and metabolic entropy(qCO_2) to a certain degree,and microbial biomass carbon exhibits an increase-decrease trend,with the metabolic entropy of each treatment is 0.18~ 4.37 times higher than that of S;Different organic fertilizers all enhance soil FDA hydrolysis activity,catalase activity,urease activity and alkaline phosphatase activity.