Abstract: Heterostructured CH₃ NH₃ PbI₃/TiO₂ composite nanowires were prepared by the slip coating method using TiO₂ nanowires synthesized via hydrothermal method. The structure and morphology of the samples were characterized by X-ray diffraction ( XRD), scanning electron microscope ( SEM) and high-resolution transmission electron microscope ( HRTEM ) . Then the molecular structure and the spectral response characteristic of the samples were studied by the Raman spectrum and Ultraviolet-visible-near infrared absorption spectrum respectively. The results show that the heterostructured CH₃ NH₃ PbI₃/TiO₂ composite nanowires, as a photocatalyst, not only can broaden the spectral response range from ultraviolet to near infrared to solve the problem of narrow spectrum band of TiO₂, but also can reduce the recombination probability of photo-generated electrons and holes, thereby it can improve the photocatalytic activity of TiO₂.