Six treatments including control(CK) without adding straw and biochar, full straw mulching(S10), half straw mulching(S5), full biochar mulching(B10), half biochar mulching(B5) and half straw+half biochar mulching(BS5) were set up for soil test. The amounts of full and half mulching were 11.6 and 5.8 t/hm2, respectively. This indoor undisturbed soil culture test in incubator at 20 ℃ to study and the effects of corn straw and biochar mulching on yellow soil nutrients and greenhouse gas emissions. The formally cultivated lasted for 32 d after pre-cultivated for 7 d. The results showed that under short-term indoor cultivation conditions, straw and biochar mulching had no significant effect on the mass fractions of soil organic matter, total nitrogen, alkaline hydrolyzed nitrogen and available phosphorus. The soil pH of BS5 was significantly higher than those of S10 and B5. Compared with CK, S10, S5 and B5 significantly reduced the mass fractions of soil available potassium. Both straw and biochar mulching increased soil CO2 cumulative emissions, and the CO2 cumulative emissions of BS5 were significantly higher than those of CK and S10. Compared with CK, the cumulative emission of CH4 in B5 decreased by 93.39%, while the cumulative emission of CH4 in BS5 increased by 21.50%. Both straw and biochar additions tended to reduce the N2O cumulative emissions, and the N2O cumulative emissions of the treatments covered with straw or biochar alone were all negative, which indicated the soil changed from a N2O emission source to a sink, and the N2O cumulative emission of S10 was significantly lower than that of CK. The straw and biochar mixed addition also tended to reduce the N2O cumulative emissions, but it was still the emission source of N2O. All treatments had potential greenhouse effect, and the global warming potential(GWP) decreased with the increase of the amounts of straw or biochar mulching. The GWP of BS5 was the highest, which was significantly higher than those of CK and S10. The potential greenhouse effect caused by the half straw+half biochar mulching treatment achieved to the summit, which is not friendly to the development of the ecological environment. Thus, straw utilization mode and usage amount should be optimized according to the actual situation in practice.