Abstract: Nanoscale ultra-precision machine tools are employed as core equipment for machining difficult-to-process materials in aerospace manufacturing. However, edge chipping and subsurface defects tend to be generated in single-crystal γ-TiAl alloys during ultra-precision machining due to high brittleness and hardness at room temperature. Nonlinear effects on the cutting dynamics of ultra-precision machine tools are introduced and the application of these alloys in high-precision components is limited. Molecular dynamics (MD) simulations were employed to systematically investigate the nanoindentation edge effect in single-crystal γ-TiAl alloys under varying indentation positions and depths. The indentation position is identified as a critical factor governing surface morphology, mechanical response, and subsurface defect evolution. When indentations are performed near the edge, the surface collapse depth increases while the affected area decreases, accompanied by significant expansion of atomic pile-up range. Concurrently, both indentation force and hardness are decreased markedly. Dislocation concentration toward the edge region, shortened Shockley partial dislocations near the edge, and localization of stress and shear strain distributions along the edge are revealed by subsurface defect analysis. The influence mechanism of edge effect on the microscopic deformation behavior of single-crystal γ-TiAl alloys is elucidated, which provides important theoretical guidance for low-damage nanoscale machining of high-performance aerospace components.