[Objective] To study the erosion laws of sandy slopes in the ecologically fragile areas of the Yellow River Basin in Shaanxi Province, determine the effective vegetation coverage to control erosion on sandy slope angles, and provide theoretical references and data support for ecological restoration and soil and water conservation of mines. [Method] By means of combination of field investigation, in-situ monitoring and numerical simulation, 12 large areas and 48 field runoff plots with three slope angles, four slope lengths and three vegetation conditions were established in Shendong sand mining site, Hechuan Town, Heyang County, Weinan City, Shaanxi Province. The Water Erosion Prediction Project (WEPP) for the sandy slope soils was constructed, and the erosion laws of the sandy slopes in the study area were simulated. Based on mutation of the increment of erosion reduction coefficient(), the effective vegetation coverage for erosion control of sandy slopes was determined. [Result] ① Based on the field in-situ monitoring data, the WEPP for sandy slope soil erosion in the study area was constructed, and the parameters of the WEPP were calibrated, obtaining the relevant parameters. ② Based on the established WEPP and the obtained parameters, the simulation of sandy slope erosion showed that there was a critical precipitation intensity (CPI), different under different precipitation, slope angles and slope lengths. When the precipitation intensity was greater than CPI, the order of runoff and sediment yield of sandy slopes under the same precipitation intensity was 70mm > 50mm > 30mm for daily precipitation; the order of runoff was 25° > 15° > 35° for slope angles, and 24.4m > 12.2m > 30.0m for slope lengths. The order of sediment yield was 35° > 25° > 15° for slope angles; if Maximum Precipitation Intensity(PImax) < 45mm/h, its order was 24.4m > 30.0m > 12.2m for slope length; if PImax > 45mm/h, its order was 30.0m > 24.4m > 12.2m. ③ Based on with 10%, the simulation showed that when the slope angle was 15° and 25°, the effective vegetation coverage to control sandy slope erosion was 20%～30%; when the slope angle was 35°, its effective vegetation coverage was 30%～40%. [Conclusion] The researches show that there is a CPI for sandy slope erosion in the Shaanxi section of the Yellow River Basin. The erosion laws of sandy slopes under different slope angles, slope lengths, precipitation and vegetation coverage were analyzed, and the effective vegetation coverage to control sandy slope erosion under different slope angles was determined. The above research results provide a basis and demonstration for the optimization of ecological restoration and soil and water conservation measures in ecologically fragile mining areas in the Yellow River Basin.