The China-Mongolia-Russia Economic Corridor (CMREC) is the key comprehensive strategic area of the “Belt and Road initiative (BRI)” that would directly accelerate the impact of human activities on land use and land cover change (LUCC). The study firstly clarified LUCC and environmental and socioeconomic driving factors in the CMREC from 1992 to 2015. It will help face the challenges of multinational sustainable development and take more targeted measures with cooperation. The results showed that the ecological environment deteriorated in the CMREC with increasing cropland, unused land, urban areas and grassland. Forest was the largest source of unused land, and urban areas consistently expanded into other areas. Compared with Mongolia and Russia, China had the highest rate of urbanization (19.68%) and experienced a prominent increase in forest revegetation (0.25%). LUCC mostly occurred along the railways, highways and rivers adjacent to vulnerability gravity centres. Overall, the relative importance of socioeconomic factors was higher than that of the environment, and railway was the most important factor. In the long term, human activity, especially national-level policy, had a direct and even far-reaching impact on LUCC.