The Salawusu River basin preserves an important record of Late Pleistocene hominin presence, crucial for understanding early human survival and migration in the semi-arid regions of East Asia. At the Shaojiagouwan site, located within this basin, abundant mammalian fossils and stone tools have been discovered. We conducted optically stimulated luminescence (OSL) dating, together with sediment grain size and pollen analyses, to establish a chronological framework and reconstruct the paleoenvironmental context. The sedimentary sequence is characterized by fluvial deposits, with OSL ages constraining the site's occupation to between 62.2 and 49.3 ka, spanning Marine Isotope Stages (MIS) 4 and 3. Evidence of hominin presence, however, is confined to 63.1-57.3 ka and can be divided into two phases. Pollen data indicate that the regional vegetation was predominantly arid steppe, reflecting a generally cold and dry climate, although conditions during early MIS 3 were relatively warmer and wetter than during MIS 4. Within this framework, three millennial-scale warm and humid phases are identified at approximately 62-61 ka, 57.5-56.5 ka, and 54-53 ka, separated by longer intervals of arid and cold climate. Our findings suggest that early humans inhabited this semi-arid region during these relatively favorable climatic optima, and may have dispersed from the area during colder and more arid intervals. The Shaojiagouwan site thus demonstrates that early humans were capable of occupying semi-arid landscapes even during the cold MIS 4 period. There may have been climate fluctuations on a millennial timescale, which have had a significant impact on human presence in the region.