Contour tillage is one of the typical agriculture tillage measures,which affects the soil erosion process of sloping farmland by affecting the slope filling and infiltration.In this study,the rainfall intensity (90 mm/h),five surface slopes (3°,5°,10°,15°,20°) and two types of slop treatments (contour tillage and flat slop) were designed through artificial simulated rainfall experiments,comprehensive comparison and analyses of indicators such as runoff rate,sediment rate,runoff sediment concentration and runoff reduction and sediment reduction benefits were carried out,compared with the flat slope,the effects the contour tillage on soil erosion process of slopeing farmland on the Loess Plateau were explored.The results showed that:(1) Compared with flat slope,the initial runoff producing time on the slope was significantly delayed by 11.58~31.91 min under contour tillage.With the increase of slope,the effect of prolonged the initial runoff producing time under contour tillage was gradually weakened.(2) The runoff rate and sediment rate were weakened under contour tillage.Compared with flat slope,the slope runoff rate,sediment rate and runoff sediment concentration under contour tillage were reduced by 11.77%~94.92%,20.69%~99.27% and 2.46%~88.40%,respectively.However,the ability of contour tillage to reduce runoff and sediment production is limited,and the runoff tate,sedimeat rate and runoff sediment concentration under contour tillage slope may be closed to or greater than that of the flat slope if ridge breaking occurs on the slope.(3) In the process of rainfall,the relationship between the accumulated sediment production and the accumulated runoff meet the linear positive correlation,and the increase of the accumulated sediment production with the accumulated runoff under contour tillage is always smaller than that of flat slope.(4) The contour tillage has good benefits of runoff and sediment reduction on different slopes,the benefits can reach 45.35%~100% and 58.92%~100% respectively,and the sediment reduction effect is obviously better than the runoff reduction effect.The results revealed the influence mechanism of contour tillage on slope erosion process,and provided a scientific basis for soil erosion control in slope farmland.