Acetylene black (AB), as a kind of carbon material with large specific surface area, low density, strong electron transferability, is supposed to have great potential for application in advanced oxidation processes (AOPs). In this study, AB was utilized as a peroxydisulfate (PDS) activator for the catalytic degradation of sulfamethoxazole (SMX) in aqueous media. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) techniques, zeta potential and Raman spectra were employed to characterize the features of AB. To verify the excellent performance of AB/PDS systems, a series of control experiments were carried out. Compared to graphite/PDS and biochar/PDS system, AB/ PDS system could complete degradation of SMX within 15 min. Besides, the effects of key factors including AB dosage, PDS dosage, initial pH and SMX concentration on SMX degradation in AB/PDS system were elucidated systematically. Furthermore, through the radical quenching experiments, it was proved that singlet oxygen (1O2) was dominantly responsible for the degradation of SMX. Finally, based on the experiment results and comprehensive analysis, a probable reaction mechanism of AB/PDS system for SMX degradation was proposed. This work suggests that AB has a good potential for tackling the hazardous pollutants in environmental remediation.