[Objective] The influence mechanism of soil water erosion on the patch distribution pattern of Stipa krylovii in a Xilamuren grassland was analysed in order to provide a theoretical basis for soil erosion control in this area. [Methods] Three distribution patterns (aggregation, uniform, and random distribution patterns) and two controls patterns (non-grazing and bare slope ) were set up by field investigation and the variance mean ratio method. Indoor simulated rainfall experiments with rainfall intensity of 30, 60, 90 mm/h, and 120 mm/h were conducted to quantify the sediment production and abortion processes on slopes with different distribution patterns. [Results] ① The distribution pattern of heavy grazing and no grazing was aggregation distribution pattern, the distribution pattern of moderate grazing was uniform distribution pattern, and the distribution pattern of light grazing was random distribution pattern. ② At 30 mm/h rainfall intensity, no runoff was produced, whereas at 60 mm/h rainfall intensity the runoff yield was in the order of bare slope ＞ aggregation distribution pattern＞ random distribution pattern＞ uniform distribution pattern＞ no grazing. For the rainfall intensity at 90 mm/h, the runoff yield was in the order of bare slope ＞ aggregate distribution pattern＞ uniform distribution pattern＞ random distribution pattern＞ no grazing. At 120 mm/h rainfall intensity, the runoff yield showed the order of bare slope ＞ aggregation distribution pattern＞ no grazing ＞ uniform distribution pattern＞ random distribution pattern. ③ At 30 mm/h, there was no sediment production. However, at 60 mm/h the sediment production rate was in the order of bare slope ＞ uniform distribution pattern＞ no grazing ＞ random distribution pattern＞ aggregation distribution pattern. The rainfall intensity at 90 mm/h resulted in sediment distribution in the order of bare slope ＞ aggregate distribution pattern＞ uniform distribution pattern＞ random distribution pattern＞ no grazing. Furthermore, at 120 mm/h rainfall intensity, the sediment distribution was in the order of bare slope ＞ no grazing ＞ aggregate distribution pattern＞ uniform distribution pattern＞ random distribution pattern. ④ At 120 mm/h rainfall intensity, the sediment reduction benefit of the random distribution pattern can be reduced by 88.76%, whereas at 90 mm/h rain intensity the flow reduction benefit of the non-grazing pattern can be reduced by 45.78%. [Conclusion] Grazing promoted the patching phenomenon of S. Krylovii, and soil water erosion intensified the formation of bare patches, which led to different distribution patterns of S. krylovii patches.