Graphene oxide (GO) and reduced GO (rGO) have become the most exciting material in the applications for photocatalysts. However, the GO composite film-based high-activity photocatalyst is usually not durable in aqueous solution. Therefore, in this paper, the non-woven polyester fabric (NWPF)-supported cuprous oxide nanoparticles (Cu2O) decorated on rGO (Cu2O/rGO@NWPF) membrane were suggested to synthesize via chemical reduction method. The Cu2O/rGO@NWPF nanocomposite was characterized by X-ray diffraction, transmission electron microscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, Brunauer-Emmett-Teller method, and energy-dispersive X-ray spectroscopy analysis. The combination of rGO and Cu2O particles supported on NWPF exhibited enhanced photocatalytic degradation of methylene blue (MB) under solar light and achieved 96% of MB removal efficiency in 120 min. The photocatalytic mechanism and the synergistic effects between Cu2O nanoparticles and rGO sheets were comprehensively investigated. The Cu2O/rGO@NWPF catalyst showed excellent stability with retained catalytic activity in four consecutive recycles. The obtained results indicated that the Cu2O/rGO@NWPF composite has a good application potential to large-scale water treatment at lakes or rivers.