A polyester fabric with durable photo-, bio-, and magneto-activities was prepared in a single-step process. In the proposed method alkali hydrolysis of polyester fabric was carried out along with the synthesis of the TiO2/Fe3O4/Ag nanocomposite, which enhanced the surface activity and nanoparticles adsorption, and produced ethylene glycol for reducing silver nitrate into nano-silver. The uniform distribution of the nanocomposite on the fiber surface was confirmed by FESEM and EDX. The fabrics showed an excellent photoactivity toward degradation of Methylene Blue under sunlight irradiation. The treated samples showed reasonable saturation magnetization and excellent antibacterial activity against Staphylococcus aureus and Escherichia coli. The tensile properties of the treated samples were enhanced as compared to the untreated fabric. Moreover, a central composite design based on response surface methodology was applied to study the influence of Fe2+/TiO2 and Ag/TiO2 molar ratio in the prepared nanocomposite, and the appropriate molar ratios for the best photoactivity were obtained.