Unlike conventional approaches where topological order is statically fixed, we demonstrate that biaxial strain can independently modulate topological order and functional responses in a Tc-adsorbed penta-hexa-silicene monolayer. Combining first-principles calculations and tight-binding models, we establish a continuous topological pathway $C=+1\to 0\to -1$ driven purely by strain, with the intermediate $C=0$ state being a gapped insulator rather than a gapless critical point. This evolution is governed by momentum-space orbital-selective engineering, which selectively reconfigures wave functions to reshape the global Berry curvature distribution. Crucially, we reveal a fundamental dichotomy: topology originates from the global phase distribution of orbital hybridization, while piezoelectric functionality arises from its local strength. This enables the coexistence of nontrivial Chern insulating states with giant electromechanical responses ($d_{11}\approx 11$ pm/V, three times that of ${\text{MoS}}_2$), establishing a paradigm for transforming static functional materials into dynamically tunable quantum platforms.

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• Magnetic anisotropy
• Surface states
• Piezoelectrics
• Silicene
• Topological materials
• First-principles calculations