Karst rocky desertification control remains challenging due to low vegetation survival and poor technical adaptability. Understanding of rock-dwelling mosses, as pioneer species, is still limited regarding their quantitative responses across microhabitats and the coupled regulatory effects of multiple environmental factors. [Objective] To explore their soil stabilization and water retention effects in Karst rocky desertification mountains and identify the influencing factors, this study focuses on exposed rock habitats in typical Karst desertification areas of Guizhou, including corn cropland, reclaimed grassland, and peach orchard land. [Method] We measured moss growth characteristics (thickness, cover, dry weight, biomass, chlorophyll), soil stabilization and water retention properties (water retention rate, soil stabilization rate), and environmental factors (light, temperature/humidity, rock surface orientation) in 267 sample plots. [Results] Results show that the peach orchard provides the best habitat for moss growth, with thickness (11.81 mm), cover (85.82%), and biomass (5.51×103 kg/hm2) 53.5%, 56.6%, and 95.0% higher than cropland in the same direction. The orchard also exhibited the highest water retention (54.18×103 kg/hm2) and soil stabilization (12.56×103 kg/hm2). On north-facing slopes (300°-345°) with 65%-80% humidity, the soil stabilization rate reached 88%-92%. Water retention decreased by 47.3% when light exceeded 6000 Lux, and soil stabilization increased with humidity and decreased with slope. [Conclusion] The synergistic regulation of land use and microhabitat determines the soil stabilization and water retention effects of rock-dwelling mosses, with excessive light and low humidity as key stress factors. The north-facing gentle slopes in peach orchards represent the optimal microhabitat, providing a basis for precision microhabitat restoration in rocky desertification areas.