Abstract: The study of erosion characteristics of loess slope is of great significance , through the scour experiment on a slope in Dongzhiyuan of Yinxi high-speed railway, the erosion state of slope under different scour duration, scour flow and gradient were obtained. The dynamic characteristics of overland flow and the sediment mechanism were further analyzed and fitted, and the following conclusions were drawn: (1) The top and bottom of the slope are more easily eroded than the middle of the slope;The slopes of 30°−60° can produce obvious erosion gullies even with small scouring intensity, and it is advisable to adopt a short the multi-stage short slopes of about 45° to reduce weaken the erosion intensity. (2) The analysis of the hydrodynamic behavior of the overland flow shows that the flow is mainly in the transitional flow zone . The average flow under the test condition velocity, is a power function with the scour flow and gradient; the Darcy resistance coefficient is negatively correlated with scour flow and gradient, and correlation with values of Re is low. (3) The average sediment concentration is positively correlated with the scour flow and gradient, and increases linearly with the scour duration. After about 20min, the sediment concentration is basically stable, and this process is the stage of development of slope channel. (4) The sediment yield is positively correlated with erosion shear stress and effective water flow power. and it approximately linearly increases with the former while it is power function with latter.