In order to improve the photocatalytic properties of ZnO, the cyclized polyacrylonitrile(CPAN) modified zinc oxide(ZnO) nanocomposites are prepared by impregnation method. The size, morphology, internal structure of ZnO/CPAN nanocomposite and ZnO nanoparticles are characterized by means of X-ray diffraction (XRD)，transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The UV-light photocatalytic activity of ZnO/CPAN is evaluated with methyl orange as model pollutant under UV-light irradiation. The results of photocatalytic experiment show that the CPAN modified ZnO can significantly improve the UV-light photocatalytic activity of ZnO particles. When the mass ratio of ZnO/CPAN is 1 000∶1, the heat treatment temperature is 150 ℃, and the heat treatment time is 30 min, the photocatalytic activity is the highest.