Gravel covering on the surface of soils can increase water infiltration and protect the soil against erosion. However, the effects of gravel covering in purple soils was less well investigated. In this paper, the influence of gravel covering on hydraulic characteristics of slope flow on purple soils in southern China was studied under simulated scouring conditions. Different gravel covering ages from 0 to 40% under three flow rates (2 L/min, 4 L/min, 6 L/min) were set up. Results showed that:(1) Flow velocity and the Froude number decreased, but the runoff depth, flow shear stress, Darcy resistance coefficient and the Manning roughness coefficient increased with the increase of cover ages. (2) The total erosion of the slope decreased negatively with the increase of cover ages. Under the small flow rates, the reduction effect of gravel covering on erosion amount of slope flow was more obvious. (3) The flow rates did not affect the relationship between gravel coverage and total erosion on the slope.