To deeply explore the relationship between altitudinal distribution characteristics of typical plant community diversity and the key soil factors in mountain ecosystems, and to disclose the important role of soil factors in plant community construction and diversity maintenance are the basis of regional biodiversity protection and the comprehensive improvement of the ecosystem service function. In the present study, redundancy analysis (RDA) and correlation analysis were applied to reveal the relationship between the vertical distribution pattern of typical plant community diversity and soil factors on the eastern slope of the Helan Mountains. It was found that the plant community diversity had an obviously vertical distribution pattern. The plant species of mixed broadleaf-conifer forest were the most abundant, with an obvious mid-domain effect. The plant diversity at different layers showed different trends with the increase of altitude and each of them showed significant differences between different altitudes (P<0.05), and the general expression was herb layer > shrub layer > arbor layer. Changes in soil factors along the altitudinal gradient were different, each of which showed significant difference (P<0.05). Among them, soil moisture content (SM), soil organic carbon (SOC), and soil total nitrogen (TN) had the largely spatial variability. The soil nutrient content of alpine shrub meadow was the highest, and there was high soil P limit in high altitude areas. Nine soil factors were strongly correlated with the plant community diversity and explained 89.68% of its ecological information. The key soil factors that impact the vertical distribution of plant diversity for different plant layers were different. In conclusion, the SOC, pH, C/P ratio, and SM were the dominant factors affecting the spatial distribution of plant community diversity on the eastern slope of the Helan Mountains.