Temperature sensitivity (Q10) of soil organic matter (SOM) decomposition is a key parameter in land surface models for predicting dryland carbon (C) responses to climate warming. This parameter is commonly attributed to substrate quality and microbial traits. In dryland ecosystems, low soil moisture limits substrate availability and alters microbial traits, yet the microbial functional strategies that mediate the temperature response of SOM across aridity gradients remain virtually unknown. Here, we investigated the changes of soil Q10 with increasing aridity from 16 dryland sites along a 3500 km aridity gradient (aridity defined as 1-aridity index, ranging from 0.4 to 0.9) in northern China. Results revealed a significant decline in Q10 values with increasing aridity. This decline was directly driven by nutrient limitations (ecoenzymatic stoichiometry) and microbial properties, including shifts in community composition and life-history strategies. In particular, microorganisms increasingly relied on stress tolerance rather than resource acquisition strategies to maintain survival, thereby dampening Q10. In contrast, climate (aridity), and substrate properties (e.g., soil organic carbon [SOC] and carbon/nitrogen ratio [C/N] influenced Q10 through indirect pathways along the aridity gradient. Collectively, these findings provide large-scale empirical evidence that aridification reduces the Q10 of SOM decomposition, suggesting that soil carbon emissions from dryland regions under future warming may be less pronounced than predicted by land surface models that assume constant or substrate-driven Q10 responses.