Abstarct: In this research, a magnetic three-component Fe₃O₄-ZnS-Ag nanocomposite was synthesized using a simple and cost-effective method in an aqueous environment. The primary objective was to investigate the photocatalytic performance of this nanocomposite in degrading methylene blue as a model pollutant in aqueous solutions. The synthesis process was carried out in three consecutive stages: first, zinc sulfide (ZnS) nanoparticles were produced via the reaction of zinc acetate with thioacetamide at 60°C for 4 hours. In the second stage, the two-component ZnS-Ag nanocomposite was synthesized by reacting silver nitrate in the presence of ascorbic acid as a reducing agent and in the vicinity of ZnS nanoparticles. In the final stage, by adding an ammonia solution to a mixture of iron (II) and iron (III) salts in the presence of the ZnS-Ag nanocomposite, magnetite (Fe₃O₄) nanoparticles with an inverse spinel structure were formed, resulting in the three-component Fe₃O₄-ZnS-Ag nanocomposite. The physical and chemical characteristics of the synthesized nanocomposite were analyzed using various identification techniques, including Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), Energy Dispersive X-ray Spectroscopy (EDS), and UV-Vis Diffuse Reflectance Spectroscopy (UV-Vis DRS). The influence of various operational parameters, such as the initial concentration of methylene blue, solution pH, the amount of nanocomposite used as the photocatalyst, and the duration of visible light irradiation on the photocatalytic degradation efficiency, was systematically studied. Furthermore, the kinetics of the degradation process and the reaction mechanism were evaluated by investigating the active species involved in the photocatalytic process. Due to the presence of the magnetite phase, the recoverability and reusability of the nanocomposite were also tested in consecutive cycles. This research can play an effective role in developing efficient, stable, and recyclable photocatalysts for the treatment of industrial wastewater containing dyes and other persistent organic pollutants.