Late Pleistocene lithic miniaturization, particularly the emergence, development and spread of microblade technology in East and Northeast Asia, has received substantial attention. Here we present a comprehensive study of the Xishantou site in Northeast China, dated to 28.3–27.4 cal ka BP. The lithic assemblage is characterized by intensive exploitation of local tuff and rhyolite and the coexistence of diversified technical systems, including core-flake and laminar reduction strategies (i.e. blade, bladelet and microblade removals). Microblades and bladelets of the site were primarily detached from burin-cores by soft-stone-hammer percussion and formed an independent reduction sequence distinct from blade reduction. Therefore, the Xishantou site provides unequivocal evidence for the appearance of microblade technology in Northeast China at the onset of Marine Isotope Stage 2 (MIS 2). This abrupt technological shift within the long-standing core-flake tradition of Northeast China may be closely linked to the eastward migration and dispersal of northern Eurasian populations, coupled with climate and environmental deterioration during the transition from MIS 3 to MIS 2. Subsequently, southward migration of populations equipped with microblade technologies to more hospitable regions was recorded in several sites during the Last Glacial Maximum (LGM), for example, at the site of Helong Dadong in the Changbaishan Mountains. These findings provide critical new insights into the emergence and development of microblade technology in Northeast China. They also shed light on the population dynamics and their adaptive strategies in response to fluctuating climate and environment during the Late Pleistocene.