Arid Central Asia (ACA) occupies the core of the Eurasian mid-latitude westerlies and represents a key terrestrial link between European loess and the Chinese Loess Plateau. Based on two representative aeolian loess-paleosol sections from the Surkhandarya River Basin in ACA, this study integrates optically stimulated luminescence (OSL) ages, soil micromorphology, geochemical proxies, and glycerol dialkyl glycerol tetraethers (GDGTs) biomarkers to investigate weathering and pedogenic processes, as well as associated paleoclimate evolution over the past similar to 50 ka. The main findings are as follows: (1) A robust chronological framework, established using OSL ages combined with a Bacon age-depth model, indicates that aeolian loess accumulated during 49.4-14.6 cal ka BP, whereas paleosol development occurred during 14.6-5.3 cal ka BP. (2) Micromorphological and geochemical evidence reveals overall weak chemical weathering dominated by plagioclase alteration, with K-feldspar remaining largely stable. Compared with the aeolian loess layer, the paleosol layer is characterized by high Chemical Index of Alteration, Chemical Index of Weathering, and Plagioclase Index of Alteration values, reduced contents of unstable minerals, enhanced secondary clay mineral formation, higher humus content, and more complex void structures, collectively indicating enhanced pedogenesis under improved hydrothermal conditions. (3) GDGTs-based temperature reconstructions indicate generally cold conditions during 49.4-14.6 cal ka BP (mean annual air temperature, MAAT similar to 3.5 degrees C). During this phase, strong wind activity coupled with weak weathering and pedogenesis favored the accumulation of thick loess deposits. This cold phase was followed by a relatively warm and humid phase during 14.6-5.3 cal ka BP (MAAT similar to 11.6 degrees C), which promoted weathering and pedogenesis, resulting in paleosol formation. The results provide a long-term environmental context for understanding human-environment interactions along the ancient Silk Road.