Abstract: Abstract: Rainfall is concentrated in summer and rainstorm often occurs in the Loess Plateau of China. Iron tailings dump with loose structure and steep slope is repeatedly eroded by rainstorms in rainy seasons, which severely affects the vegetation restoration. This study explored the influence of intermittent rainfall on hydrodynamics characteristics of erosion on reconstructed slopes of iron tailings in order to decrease soil and water loss of iron tailings. Soil or mushroom residue was added to tailings in order to improve the properties of iron tailings. A total of six reconstructed slopes were constructed and they included loose tailings (LT), crusty tailings (CT), tailings incorporating mushroom residues (TM), tailings incorporating soil (TS), tailings incorporating soil and mushroom residues (TSM) and soil (S). Indoor artificial simulated rainfall was used to study the erosion characteristics and hydrodynamic factors of the six reconstructed slopes at 25°, 30° and 35° under intermittent rainfall. Three rainfall events of 60, 90 and 120 mm/h were carried out on the same slope. The results showed that 1) the runoff rates of the six substrates increased continuously with the increases of rainfall events but the sediment yield rate was different: sediment yield rate of LT, CT and TS increased continuously with high-sediment yield and that of TS, TSM and S increased first and then decreased as a whole with low sediment yield. The difference in sediment yield among the six slopes was significant, and the difference of runoff was not significant. 2) Under intermittent rainfall condition, the differentiation in slope micro-topographic morphology was much distinct. LT, CT and TS easily produced rills and the rills were developed rapidly, evolved into the rills with smaller width-depth ratio; the rills on TM, TSM and S evolved slowly, and finally the width-depth ratio of rills on S was larger; TM and TSM produced many small pits of mushroom residues evenly, and the rills were rare and shallow. The gully area and relief amplitude continued to increase with the increase of rainfall events while the gully density sharply increased then some of the substrates decreased and the others still increased. 3) The slope of the six slopes produced laminar flow, and most of substrates were supercritical flow. With the increase of rainfall events, the flow velocity and runoff power showed increasing trend while the Darcy-Weisbach resistance coefficient and Manning roughness coefficient showed decreasing trend. The runoff shear stress didn't show obvious trend. The hydrodynamic driving factors of erosion were different among the six slopes and the runoff and sediment yield were well simulated by logarithmic, linear or power functions. LT and CT had the most serious erosion morphology on the slope and S had the obvious effect on reducing runoff. TM, S and TSM could reduce sediment loss. Among TM, S and TSM, TM was the best for reduction of sediment loss. Therefore, in the iron tailings reclamation area lack of soil resources, the addition of mushroom residues and small amount of soils is an effective way to decrease erosion and facilitate vegetation restoration.