Abstract: Superiority strains G1-1 was obtained from the sludge samples collected from the Triassic Yanchang 6 reservoir and the oil-displacement capacity was tested. The impact of injection parameter on microbial enhanced oil recovery was researched. Through the artificial core flooding experiments, the best microbial injection slug was optimized to be 0.3-0.45 PV, and the best injection speed was water flooding speed in field trial of 0.48 m/d. The effect of section increasing oil by plug injection was the best, which could improve oil recovery up to 15.24%. The experiment results show that the selected strains have good compatibility with reservoir and obvious stabilizing oil production by water control effect.