Since the Cenozoic, the Tibetan Plateau has experienced large-scale uplift and outgrowth due to the India–Asiacollision. However, the mechanism and timing of these tectonic processes still remain debated. Here, using apatite fissiontrack dating and inverse thermal modeling, we explore the mechanism of different phases of rapid cooling for differentbatholiths and intrusions in the southeastern Tibetan Plateau. In contrast to previous views, we find that the coeval graniticbatholith exposed in the same tectonic zone experienced differential fast uplift in different sites, indicating that the presentTibetan Plateau was the result of differential uplift rather than the entire lithosphere uplift related to lithospheric collapseduring Cenozoic times. In addition, we also suggest that the 5–2 Ma mantle-related magmatism should be regarded as thecritical trigger for the widely coeval cooling event in the southeastern Tibetan Plateau, because it led to the increase inatmospheric CO2 level and a hotter upper crust than before, which are efficient for suddenly fast rock weathering anderosion. Finally, we propose that the current landform of the southeastern Tibetan Plateau was the combined influences oftectonic and climate.