Persulfate (PDS)-based advanced oxidation processes have attracted considerable attention because of their excellent pollutant removal performance. However, precisely regulating the PDS activation pathway to shift conventional radical oxidation toward a highly selective nonradical oxidation process remains a major challenge in environmental catalysis. Herein, we report a curvature-engineered Zn single-atom catalyst (C-ZnN4) for regulating PDS activation through a nonradical electron-transfer pathway (ETP). A comparative study between curved Zn single-atom sites (C-ZnN4) and planar Zn single-atom sites (P-ZnN4) revealed that atomic-scale curvature effectively modulated the local electronic structure of the Zn active centers, redistributed the electron density, and enhanced interfacial electron transfer. The C-ZnN4/PDS system exhibited excellent acetaminophen (APAP) degradation performance, with a pseudo-first-order rate constant 19.22 times higher than that of the planar ZnN4 system. Electron paramagnetic resonance (EPR), quenching experiments, electrochemical measurements, in situ Raman spectroscopy, and theoretical calculations collectively demonstrated that the ETP dominated APAP degradation in the C-ZnN4/PDS system, contributing 99.3% to the overall process. Density functional theory calculations further confirmed that the curved structure enhanced PDS adsorption at the Zn single-atom sites and promoted interfacial electron transfer between APAP and PDS through the Zn active centers. In addition, the C-ZnN4/PDS system exhibited excellent cycling stability and robust continuous-flow treatment performance, maintaining an APAP removal efficiency of 99.47% after 120 h of continuous operation. This study elucidates the critical role of atomic-scale curvature in regulating the catalytic mechanism of single-atom sites and provides a theoretical basis and design strategy for developing efficient and highly selective nonradical advanced oxidation systems for water pollution control.