Study of desert ecosystem diversity is of great significance for maintaining the stability of desert communities. As an important component of biodiversity, plant diversity plays an important role in maintaining the function and stability of community ecosystem. In arid and semi-arid areas, the increase in drought will have an important impact on plant diversity, which in turn will affect the stability of the community. Therefore, soil water content is a key factor affecting the diversity and community stability of desert plant. We studied the changes of plant diversity, community stability and other soil factors along the soil water gradient in Ebinur Lake basin. From July to August in 2017, a 30 m×3600 m transect was established north of the Aqikesu River and divided into sixty 30 m×30 m quadrats. In each plot, plant abundance, height, and diameter at breast height were recorded. Soil characteristics were analyzed, including water content(WC), soil pH(pH), soil salinity (SA), soil organic matter(SOM), total nitrogen(TN), total phosphorus(TP), available phosphorus(AP), and nitrate nitrogen(NN). Firstly, the sampling plots were divided into three water gradients by cluster analysis and included high water (W1), middle water (W2), and low water(W3) gradients. Secondly, we studied the changes of plant diversity, community stability and other soil factors along the soil water gradient. Finally, we screened the soil factors and added them to the structural equation model(SEM) to discuss the main soil factors affecting plant diversity and community stability under different water gradients. The results showed that:(1) with the decrease of soil water content, Shannon-Wiener index (H), Simpson index (D), Pielou index (J), Margalef index (R) and Inverse coefficient of population density variation (ICV) all showed a downward trend. Moreover, when the soil water content was lower than 4.65%, the overall diversity and community stability of desert plants decreased significantly (P<0.05); (2) There are differences in soil factors affecting plant diversity under different water gradients. The high water gradients were soil nitrate nitrogen and soil organic matter, medium water gradients were soil pH, and low water gradients were soil total nitrogen and soil organic matter; (3) Soil factors (soil salinity and organic matter) have a significant impact on community stability only the soil environment is appropriate (P<0.01); (4) Species diversity has significant effects on community stability under three gradients (P<0.001). There was a positive correlation between plant diversity and community stability. The research results are of great significance to the restoration of vegetation diversity and community stability in the study area.