Abstract: The development of a combined photocatalytic system with peroxymonosulfate (PMS) has great potential applications in the degradation and treatment of aqueous organic pollutants. Herein, a Co₃O₄-ZnO/rGO was prepared by a hydrothermal method using cobalt acetate, zinc acetate, and reduced graphene oxide (rGO) as the main raw materials. The physical and chemical characteristics of the obtained catalyst were analyzed using XDR, XPS, SEM, and FT-IR. The photocatalytic features and capacities of the catalytic materials to activate PMS were investigated. Co₃O₄-ZnO/rGO exhibited stronger photocatalytic activity and ability to activate PMS than Co₃O₄/rGO or ZnO/rGO, and significantly improved the ability of PMS and photocatalysis to synergistically degrade rhodamine (RhB), with a degradation rate of 90.40% within 40 min. The mechanism of RhB degradation was proposed based on characterization of materials, evaluation of RhB degradation efficiency, and analysis of the active species involved. The unique particle/sheet structure of Co₃O₄-ZnO/rGO provides a large number of active sites, and the formation of heterojunctions between Co₃O₄ and ZnO improves carrier separation and transport in the reaction system. Our study offers a reference for designing more effective heterojunction catalysts based on the combination of PMS and photocatalytic technology.