Solid–electrolyte interphases (SEIs) are essential for stabilizing metal anodes in aqueous zinc (Zn) batteries (AZBs), yet their formation remains intrinsically uncontrolled, leaving the interphase vulnerable to dissolution and water-driven parasitic reactions. Herein, we report an electron-induced molecular programming strategy that uses only 1 mM of 4-bromobenzenediazonium tetrafluoroborate (BDTF) to in situ construct a Zn²⁺-favored molecular lock on the ZnF₂-rich SEI surface. Electrochemically generated p-bromoaniline becomes molecularly woven into the inorganic layer, forming an ultrathin molecular-lock shell (∼1 nm) atop a graded hybrid SEI. Through N–Zn coordination coupled with Br-induced interfacial polarization, the molecular lock reorganizes the local electrostatic environment, stabilizes ZnF₂, limits water access, and promotes desolvation-facilitated Zn²⁺ transport. As a result, the programmed SEI enables highly reversible Zn plating/stripping with a 99.8% average Coulombic efficiency, and stable cycling under 80% depth of discharge at 10 mA cm⁻². Moreover, it displays broad cathode compatibility, extending cycling stability in vanadium-, manganese-, and iodine-based full cells. In Ah-level pouch cells with ultrahigh vanadium-based cathode loading (21 mg cm⁻²), the system delivers 1.2 Ah with 81% retention after 100 cycles, surpassing state-of-the-art aqueous Zn batteries that typically fail at high mass loading.