Rocky desertification in Southwest China harms soil and plants. Soil properties were studied in different rocky desertification levels. Soil nutrients like N, P, and K affect plant diversity. Shrub species richness is higher than herb species. Soil pH and Ca increase with rocky desertification grade. Herb diversity decreases then increases, while shrub diversity shows the opposite trend. Soil nutrients play a key role in shaping plant communities in rocky desertification areas.