【Objective】 Under the influence of extreme rainstorms, the slope of a dump site(a typical artificial re-plastic landform) is prone to geological disasters such as landslides and debris flow. This has resulted in soil erosion and vegetation restoration difficulties in the nearby mining areas. Therefore, to understand this phenomenon, this study focuses on the soil of an open-pit coal mine as the research object. 【Method】 The soil erosion process on the slope of the dump site was studied using an artificial simulated rainfall test. Runoff and sediment samples were collected when the slope of the dump site began to produce runoff after rainfall. Data on the flow velocity, flow width, flow depth, runoff, sediment content, etc., were collected once every 3 min. The runoff and sediment samples were collected and the volume was measured with a graduated measuring cup. Then, the cups were allowed to stand, and when the upper liquid was static and precipitated, the liquid was removed, and the erosion was measured by drying method (105 ℃). Furthermore, Reynolds number, runoff shear force, runoff power, and soil erosion rate were calculated from the collected data. Based on the data analysis of different rainfall intensities (50, 75, 100 mm·h^-1) and vegetation coverage (0%, 40%, and 70%), the change characteristics of slope denudation rate with water flow generation time and the quantitative relationship between soil denudation rate and hydrodynamic parameters were explored. 【Result】 (1) The soil erosion rate increased with the increase of rainfall intensity, and decreased with the increase of vegetation coverage. The contribution rates of the two factors to the soil erosion rate were 50% and 36%, respectively. (2) Under the three rainfall intensifies, the total sediment yield of 70% vegetation coverage decreased significantly by 18%~27% and 84%~87% compared with 0% (P < 0.05), respectively. Compared with 50 mm·h^-1, the total sediment yield of 100 mm·h^-1 was significantly increased by 1940~2530 mL and 66.92~386.14 g, respectively (P < 0.05). (3) At 0%, 40%, and 70% vegetation coverage, soil denudation rate showed a significant power function relationship with Reynolds number, runoff shear force, and runoff power(P < 0.01) while the hydrodynamic parameters showed a significant linear positive correlation (P < 0.01). In terms of goodness of fit, the vegetation coverage of different hydraulic parameters was 70% > 40% > 0%. The fitting effect between soil denudation rate and runoff power was the most significant, and the determining coefficient R² was 0.894, followed by runoff shear force. 【Conclusion】 Rainfall intensity is the main factor affecting soil erosion rate and with an increase in rainfall intensity, the rate of soil erosion also increases. The increase in vegetation cover led to a decrease in soil erosion rate. Under 70% vegetation coverage, the regression relationship between runoff power and soil erosion rate was most significant, and this parameter was the best hydraulic index to describe runoff erosion of the mine dump slope.