[Objective] The impact of different gravel contents on soil erosion of engineered deposit slopes were explored in the sandy soil region of Northern Shaanxi Province under continuous rainfall conditions in order to provide data support and theoretical references for soil erosion control in production and construction projects. [Methods] Indoor rainfall experiments were conducted to study the hydrodynamic, runoff, and sediment characteristics of engineered deposit slopes with varying gravel contents (0%, 10%, 20%, 30%, 40%). [Results] ① Under the same rainfall intensity, the initial runoff time on the engineered deposit slopes showed a decreasing trend with the increase of gravel content, with ranges of 27.22%—64.62%, 35.09%—71.70%, 47.37%—78.77%, and 51.75%—82.31%, respectively. The runoff coefficient during subsequent rainfall events exhibited a “rapid increase-stable fluctuation” trend, and the average runoff coefficient increased significantly with increasing gravel content and rainfall duration. However, the peak value of runoff decreased with increasing gravel content, and the occurrence time of the runoff peak was gradually advanced. ② The Reynolds index for all experiments ranged from 74.13 to 165.05, all of which were below 500, indicating that the flow type was laminar flow, while the Froude number ranged from 2.14 to 3.7l indicating rapid flow. The shear force, flow power, and unit flow power increased with increasing rainfall time. ③ The ranges of erosion modulus on the engineered deposit slopes were 0.45—6.73, 0.13—4.09, 0.25—1.26, 0.14—0.96, and 0.13—0.88 g/(m²·min), respectively. The sediment reductions for each gravel content were 36.06%, 49.05%, 55.23%, and 56.62%, respectively. The highest gravel content (40%) resulted in the lowest soil erosion intensity of the engineered deposit slopes in the sandy soil region. [Conclusion] Gravel coverage on engineered deposit slopes of sandy loam soil significantly reduces soil erosion rate, thereby achieving soil retention and maintaining high sediment reduction benefits.