This study aims to explore the effect of different distribution modes of shrubs and herbs on the distribution characteristics of eroded sediment particles. The research object was selected as the slope with the cinnamon soil planted with shrubs (Lespedeza bicolor Turcz.) and herbs (Medicago sativa L.). The indoor simulation rainfall experiments were performed on the cinnamon soil slopes, with three types of rainfall intensity: 30, 60, and 90 mm/h, three types of vegetation coverage as the ratios of shrubs and herbs: 1:2 (denoted as Ⅰ), 2:1 (denoted as Ⅱ) and 1:1 (denoted as Ⅲ), and three types of vegetation patterns as the shrub locations: an up-slope (denoted as US), a middle-slope (denoted as MS), and a low-slope (denoted as LS). The experimental data of bare slope was used as the control group. A systematic analysis was made to determine the distribution characteristics of eroded sediment, and the interaction between the vegetation coverage and vegetation patterns under rainfall conditions. The results showed that: 1) The silt was the main particle composition of the eroded sediment on the slope, with a mean value of 73% under the various distribution of shrubs and herbs. The eroded sediment gradually coarsened with the increase in the rainfall intensity. Specifically, the maximum content of silt particles of 84.8% was found on the slope with the LS shrubs and the Ⅱ vegetation cover under the 90 mm/h rainfall intensity. Conversely, the minimum content of silt particles of 40.4% was on the slope with the US shrubs and the Ⅲ vegetation cover. 2) There was a significant effect of shrubs and herbs distribution on the Mean Weight Diameter (MWD), Fractal Dimension (D), and Enrichment Ratio (ER). The MWD varied from 0.023 to 0.078 mm, and the D varied from 2.184 to 2.740 in different distributions of shrubs and herbs. The size trends of D and ER were opposite to the MWD. Furthermore, the MWD and D values depended mainly on the content of coarse particles, including very fine, fine, and medium sand. Meanwhile, the fine particles (clay and silt) were enriched in the eroded sediment, whereas, the large particles (fine and very fine sand) were not easily lost on the slope. 3) The shrubs and herbs on the slope presented a relative impact on the fine-grained eroded sediment. The vegetation also greatly contributed to the sediment particles for a strong sorting action. However, there was no significant effect of the interaction of shrubs and herbs coverage and pattern on the sorting of sediment particles. The best effect of soil and water conservation on the slope runoff sediment was achieved, when the shrubs were located at the bottom of the slope, the fraction of coverage of shrubs was 50%, and the fraction of coverage of herbs was 25% (i.e., II-LS). This finding can provide a promising theoretical reference and a technical basis for the implementation of soil and water conservation measures in the earth-rock mountainous areas with cinnamon soil.