Abstract：Cold-arid regions cover more than half of China's land area, but their climatic and environmental conditions have long constrained agricultural development. To fully exploit the advantages of agroclimatic resources, expand the endowment of climatic resources, and explore localized agricultural development pathways, it is essential to scientifically understand the distribution characteristics of agroclimatic resources and study the intrinsic traits of climatic resources in China’s cold-arid regions. Based on 4 km resolution meteorological data from 2000 to 2020, this study constructed a Cold-Arid Synergy Index (CASI), integrating the dual dimensions of thermal limitation (Thermal Restriction Index, TRI) and moisture stress (Hydrological Stress Index, HSI). This index quantifies the spatial differentiation pattern of cold-arid interactive stress and analyzes the contribution mechanisms of its dominant factors. The research found that cold-arid agroclimatic zones in China account for 16.42% of the national land area, exhibiting a northeast-southwest belt-shaped distribution. CASI-based zoning revealed a five-category gradient: Grade I zones (extreme stress) are primarily located on the Tibetan Plateau; Grades II and III zones (Hexi Corridor, Inner Mongolia Plateau) form the main body of the agropastoral ecotone; Grades IV and V zones (Northeast Plain to Central Gansu) have optimal hydrothermal matching and are suitable for large-scale agricultural production. At the provincial scale, provinces such as Gansu and Inner Mongolia have over 40% of their area classified as cold-arid, with CASI standard deviations reaching 0.10–0.18, highlighting the climatic sensitivity of transition zones. LISA spatial autocorrelation analysis indicated that 28.52% of the cold-arid area comprises Low-Low clusters (LL-type), representing core advantageous production areas; 28.24% belongs to High-High clusters areas (HH-type), forming agroclimatic high-risk islands requiring targeted enhancement of climate resilience. Dominant factor analysis revealed that aridity-dominant zones account for 73%, while cold-dominant zones account for 27%, with the contribution of cold stress significantly increasing with elevation. The CASI index system constructed in this study provides a novel methodology for cold-arid agroclimatic zoning, while the zoning results offer a scientific basis for optimizing agricultural spatial layout, enabling precision resource allocation, and developing specialized industries within cold-arid regions under the context of climate change.