A series of flower-like Fe0-Fe3O4@MoS2 composite catalysts were successfully synthesized by reducing Fe0 on the surface of Fe3O4 hollow spheres and coating with MoS2 to activate peroxomonosulfate (PMS) for tetracycline hydrochloride (TC) degradation. Adding Fe0 increased the Fe2+ content, and the surface-coated 1T/2H mixed phase MoS2 enhanced the redox cycle of Fe (II)/Fe (III) and the reactivity of the heterogeneous system. Subsequently, the quenching experiments showed that radical and non-radical pathways were present in the Fe0-Fe3O4@MoS2/PMS system, and O2−· and 1O2 were dominant in the degradation. Moreover, the experimental results demonstrated that Fe0-Fe3O4@MoS2 exhibited excellent degradation efficiency (96.81%) and anti-interference capability against anions and humic acid. On this basis, the reaction mechanism was analyzed, and three possible degradation pathways were proposed by LC–MS to detect intermediates of TC.