【Objective】 Soil degradation on the Loess Plateau has become a major obstacle to regional sustainable development. Therefore, assessing soil quality is crucial for the conservation and rational use of soil resources. 【Method】 Based on data for soil physical, chemical, and biological indicators related to soil quality, this study applied the Soil Quality Index method to carry out a comprehensive and systematic evaluation of soil quality across the Loess Plateau. 【Result】 The results indicate that(1)soil quality exhibits a three-tier spatial distribution: the lowest quality occurs in the Mu Us Sandy Land and arid northwest, moderate quality in the central–western hilly zones, and the highest quality in the southern, eastern, and northern mountain regions as well as the loess hilly–plain area; (2)under different land-use and geomorphic conditions, soil quality declines in the order forestland > cropland > grassland > unused land and mountain > loess plateau > plain > loess hills, and within major agricultural areas, cropland quality decreases in the sequence Fen-Wei Plain > Yinchuan Plain > loess plateau > loess hills; (3)soil nutrients(total nitrogen, organic matter, total phosphorus), biological activity(nematode abundance, soil respiration intensity), and texture(clay and silt content)jointly dominate soil quality. 【Conclusion】 This study reveals that soil quality on the Loess Plateau follows a distinct three-tier spatial pattern with significant differences among land-use types and landforms, primarily governed by nutrients, biological activity, and texture. These findings provide an important foundation for the conservation and improvement of soil resources on the Loess Plateau.