This study investigates the molecular mechanisms underlying drought-resistant heterosis (DRH) in the elite hybrid rice HY73. Utilizing a quantitative lysine acetylome profiling approach on flag leaves of HY73 under well-watered (WW) and drought-stressed (DS) conditions, we aimed to unravel the role of protein lysine acetylation (Kac) in carbon metabolic reprogramming during drought adaptation. Critically, we identified phosphoglucomutase (OsPGM3) as a key metabolic switch whose K155 acetylation (K155ac) is dynamically downregulated under DS. This regulation orchestrates a strategic carbon reallocation, optimizing glucose-6-phosphate (G6P) flux towards lipid biosynthesis for stress resilience (MOS-AcCoA-FA/PR pathway) while maintaining efficient glucose-1-phosphate (G1P)-mediated sucrose export for yield potential. This dataset provides valuable insights into the sophisticated post-translational regulatory network that underpins superior DRH and yield stability in hybrid rice under water scarcity.