Vegetation spatial heterogeneity arises from the coupling interactions of Earth's multiple spheres. Previous studies have emphasized zonal controls by climate, topography, and hydrology, the non-zonal regulatory mechanisms mediated by lithospheric substrates through lithology-soil interfaces remain inadequately explored. This study investigates the Luoshan region in Ningxia province, a typical arid area characterized by pronounced vegetation heterogeneity, integrating remote sensing imagery, geological maps, and field measurements to unravel the cascading effects of geology and landforms on vegetation patterns. Our findings demonstrate that NDVI spatial distribution displays a distinct ring-shaped structure, with high-value zones (NDVI>0.6) aligning with knickpoints of radial drainage networks. This indicates the undisturbed mountainous cores, that are resistant to headward erosion, sustain high-coverage vegetation through effective soil-water conservation. Lithology governs vegetation heterogeneity by regulating soil nutrient availability and moisture retention. The Miboshan Formation (Omb) weathering zone, characterized by high water-holding capacity and nutrient retention, fosters montane meadow-steppe and forests (NDVI>0.6). Eastern alluvial-proluvial deposits (Qp3pl), despite their high nutrient content, exhibit low water retention, resulting in only sparse desert and desert-steppe dominance (NDVI<0.4). Conversely, western Malan loess (Qm) compensates for nutrient limitations with superior moisture retention, supporting typical steppe and desert-steppe (0.2