Glaciers in the Yarlung Zangbo Downstream Basin (YZDB) are sensitive to global climate change. The equilibrium-line altitude (ELA) is a key indicator of glacial development. Current models for simulating the meteorological ELA underestimate the extent of glacial advance during the Last Glacial Maximum (LGM) in the YZDB and cannot explain the large-scale glacial extension compared with the Yarlung Zangbo Midstream Basin (YZMB). In this study, the distribution of ELA in the LGM is reconstructed using high-resolution 80-km ECHAM5 simulations and empirical relationships between temperature and precipitation. Changes in ELA between the LGM and pre-industrial era (PI) are compared. Our simulated ELA closely fits the published field data. In the YZDB, simulated LGM ELAs range from ca. 3500 m to over 4900 m, representing declines of ca. 300-950 m. The ECHAM5 simulations better reflect the complex topographic features than most coarse-resolution climate models, and the ELA distribution is controlled by the spatial arrangement of river valley systems and mountain ranges and their impact on precipitation. Compared with the PI era, most of the monsoon precipitation in the LGM was concentrated in the YZDB, which is the main driver of glacial extension and the differential response of the downstream and midstream basins.