In this study, a novel method for the high-performance treatment of oily wastewater was introduced using a tungsten (VI) oxide (WO3)/MXene composite membrane based on poly (arylene ether sulfone) (PAES). Composite membranes were fabricated with superhydrophilic (SH) and superoleophobic (SO) characteristics, which allow for the high-performance treatment of oily wastewater. The fabricated composite membrane can also photodegrade organic types of pollutants with just a short period of UV, enabling self-cleaning and anti-fouling properties. Moreover, the comprehensive characterization of the composite membrane through FTIR, SEM, and XRD analyses yielded valuable insights. The FTIR analysis revealed the characteristic peaks of WO3, MXene, PAES, and the synthesized composite membrane, providing essential information on the chemical composition and properties of the materials. The XRD results demonstrated the crystal structures of WO3, MXene, PAES, and the synthesized composite membrane, further enhancing our understanding of the composite membrane. Additionally, the SEM images illustrated the surface and cross-section of the fabricated membranes, highlighting the differences in pore size and porosity between the PAES membrane and the WO3–MXene composite membrane, which directly impact permeate flux. The study showed that the composite membrane had a remarkable recovery time of only 0.25 h, and the efficiency of the separation process and water flux recovered to 99.98% and 6.4 L/m2.h, respectively. The joint influence of WO3 and MXene on composite membranes degraded contaminants into non-polluting substances after sunlight irradiation. This process effectively solves the treatment performance and decrease in permeate flux caused by contamination. The technology is membrane-based filtration, which is a simple and advanced method for treating polluted water. This innovative work offers promising solutions to address water pollution challenges and holds potential for practical applications from a self-cleaning and anti-fouling point of view.