Monolayer tungsten trioxide nanosheets (ML-WO₃) were prepared via the space-confined strategy and then compounded with TiO₂ to obtain ML-WO₃/TiO₂ nanomaterials, which were used for the photocatalytic degradation of rhodamine B under simulated solar light. The compositional structure and optical features of ML-WO₃/TiO₂ were characterized by means of SEM, TEM, HRTEM, XRD, UV-Vis and PL. The results showed that the ML-WO₃/TiO₂ overcame the defect of large band gap of pure TiO₂ and exhibited stronger absorption performance than ML-WO₃ and TiO₂ in the full wavelength solar light, and there was a remarkable synergistic relationship between ML-WO₃ and TiO₂. The active species capture experiments showed that .OH and .O_2^- free radicals were the main active species for RhB degradation. The Z-scheme heterojunction charge transfer pathway constructed between ML-WO₃ and TiO₂ can ensure efficient separation and recombination of photogenerated carriers. The photocatalytic activity of the ML-WO₃/TiO₂ composites could still approach 80% after 5 cycles of experiments, with good photochemical stability. The possible degradation pathway of RhB was speculated by the detection of RhB intermediates by HPLC-MS.