The Qilian Mountains are a crucial ecological security barrier in arid northwestern China, yet the coupled response of ecosystem services (ESs) to compound extreme climate events remains poorly quantified. Four ESs (habitat quality, water yield, soil retention, and water conservation) were quantified using the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model and coupled with pixel-scale extreme climate indices from 2000 to 2023. Regionally, ESs remained stable but varied locally. Habitat quality remained relatively stable, while water yield and water conservation declined after 2008. By 2023, water yield, water conservation, and soil retention decreased to 511.81 mm, 315.35 mm, and 1521.81 t/ha, respectively. The Trend-Free Pre-Whitening Mann-Kendall (TFPW-MK) test and the spatial Gini coefficient showed that extreme precipitation exhibited stronger intensification and spatial clustering than extreme temperature. Optimal geodetector and ridge regression multimodel framework indicated that ES changes were primarily driven by precipitation frequency and intensity. A framework combining Peaks Over Threshold, the Generalized Pareto Distribution, and a trivariate vine copula identified three joint risk types: high water yield with low soil retention, high water yield with low water conservation, and low water conservation with low soil retention. Under compound triggers of annual maximum 1 day precipitation (Rx1day) > 30.31 mm and days with precipitation >= 20 mm (R20) > 2.47 d, high-risk areas constituted 0.7%, 0.6%, and 3.1%, respectively. Medium-risk zones were significantly enriched in shrublands and forests (enrichment indices: 1.96 and 1.36). Hazard-Exposure-Vulnerability (H-E-V) zoning delineated eight priority areas and a high-risk corridor across Minle, Shandan, Qilian, and Sunan, encompassing over 40% of all high-risk zones. These findings provide a transferable framework for linking climate triggers to ecosystem service risk zoning and support risk-informed, zoning-based management in cold arid mountain ecosystems.