Arid inland oases depend on groundwater, yet many basins face co-occurring water scarcity, salinization risk, and ecological vulnerability. We examined the Cherchen River Basin to clarify how aquifer structure, water-table position, and water quality jointly constrain sustainable oasis use. We asked three questions: what are the basin-scale patterns of aquifer architecture and groundwater depth, how do groundwater, irrigation water, and surface water qualities vary spatially, and where salinization is risk most acute. We hypothesized that shallow phreatic levels coincide with salinization hotspots and that proximity to human activities is associated with degraded groundwater quality. Using integrated field surveys, pumping tests, hydrochemistry, geophysics, and GIS mapping, we produced basin-wide layers of groundwater depth and quality and evaluated irrigation suitability against national standards. The aquifer is a thick, single porous system with marked south-north gradients; shallow water tables dominate irrigated zones, indicating high evaporative risk. Groundwater quality is spatially heterogeneous, with localized degradation near human activity; most irrigation sources are usable, although outliers with high salinity and chloride pose soil risks. Surface water quality is generally acceptable but nutrient enrichment warrants attention. The results provide a decision basis for targeted drainage, irrigation efficiency upgrades, and groundwater protection to mitigate salinization and support long-term ecological security in arid inland basins.