Enhancing the activation efficiency of peroxymonosulfate (PMS) to generate more reactive oxygen species (ROS) is crucial for improving the catalytic performance of Fenton-like reactions. Strategies on the regulation of active sites and the enhancement of interfacial electron transfer from catalysts to PMS have become central to achieving effective PMS activation in Fenton-like catalysis. In this work, single-atom M-doped sulfur vacancies (Sv)-MoS2 (M = Co, Mn, Ni, Cu, and Zn) catalysts with atomic-level asymmetric M-SV-Mo sites are proposed for efficient PMS activation and the degradation of organic pollutants. Among these catalysts, the Co-SV-MoS2 exhibited excellent catalytic activity and stability, resulting in a removal efficiency of ≈100% for Rhodamine B (RhB) within just 6 min. Density functional theory (DFT) calculations revealed the construction of asymmetric Co-SV-Mo sites effectively enhanced the electron density near the Fermi level, facilitated more electron transfer to PMS as well as lengthened the O-O bond of PMS, thereby significantly promoting the generation of ROS. This work provides a strategy for regulating atomic-level active sites and a novel perspective for developing advanced Fenton-like catalysts.