Nonradical oxidation based on peroxydisulfate (PDS) activation has attracted increasing attention for selective degradation of organic pollutants. Herein, topological defects were introduced into biochar (BC) via removing N atoms in N-doped BC (NBC) in an attempt to improve the nonradical catalytic performance. Compared to the pristine BC and NBC, the introduction of topological defects could achieve up to 36.6- and 8.7-times catalytic activity enhancement, respectively. More importantly, it was found that the catalytic activity was dominated by topological defects, which was verified by the significant positive correlation between the pseudo-first-order rate constants and the content of topological defects. Theoretical calculations suggested that topological defects enhanced the electron-donating ability of BC by reducing the energy gap, which made the electrons transfer to PDS molecules more easily. As a result, holes were generated after the carbon defects lost electrons, and induced a nonradical oxidation process. Benefiting from the merits of nonradical oxidation, the developed BC/PDS system showed superior performance in removing electron-rich contaminants in the presence of inorganic anions and in the actual environments. This study not only provides a potential avenue for designing efficient biochar-based catalysts, but also advances the mechanism understanding of nonradical oxidation process induced by carbon defects.Graphical