Abstract: In order to quantitatively evaluate the preventing wind erosion effect of conservation tillage farmland affected by vegetation coverage and residual stubble height, aerodynamics roughness and resistance to wind erosion efficiency were made as evaluation index. In-situ test was conducted at conversation tillage and autumn –ploughed farmland by using movable wind erosion tunnel in Wuchuan County in Inner Mongolia. It is showed that aerodynamics roughness and resistance to wind erosion efficiency increase and the effect on preventing wind erosion strengthens with the increase of vegetation coverage and residual stubble height. The average resistance to wind erosion efficiency of conversation tillage farmland can reach 80.55%. It has a good resistance to wind erosion efficiency, when the residual stubble height is 30 cm and vegetation coverage is 50%. So, conservation tillage farmland should have more than 50% vegetation coverage and 30 cm residual stubble height to prevent and treatment soil wind erosion of farmland efficiently.