The Taklamakan Desert is a prominent Asian desert. The dynamic sand mobility has intensified soil erosion, degradation, and desertification in the surrounding areas. China has invested substantial resources in combating desertification to prevent its outward spread. Satellite-based monitoring of large-scale land-cover changes in desert oasis transition zones, the frontline in the battle between humans and deserts, provides highly credible evidence for ecological restoration. Greening trends have been identified using satellite-derived vegetation indices, suggesting a potential reversal of desertification. However, the spatiotemporal distribution of sandy land derived from long-term remote sensing imagery, which can directly reflect the human desert battle, has been limited. Therefore, in this study, we analyzed the spatiotemporal dynamics of sandy land in the Taklamakan Desert Oasis Transition Zone (TD-OTZ), a frontline in the human-desert battle, over the last two decades using time-series Landsat imagery (2003-2022). The driving effects of topographic, meteorological, hydrological, and socioeconomic factors on sandy land change were evaluated using a geographical detector model with optimal parameters. There has been significant greening in the TD-OTZ, with reduced sandy land being primarily converted into grassland (70.87%), cropland (6.94%), and woodland (5.19%). A decreasing trend is observed in the hinterland area of the Taklamakan Desert. The boundary of the Taklamakan Desert in the transitional zone exhibits a continuous inward contraction, particularly in the western region. Analysis of the boundary changes indicated that the desert hinterland area shrank by approximately 5,295 km2 during the study period. Although the driver analysis indicated that meteorological factors were the primary factors dominating desertification, the contribution of desertification-combating practices may have been underestimated, as they are difficult to quantify. This study provides a comprehensive assessment of spatial variations in sandy land around the Taklamakan Desert over the past two decades, signifying a positive greening trend and inspiring continued efforts to combat desertification.