: Increasing the world's population and industrial growth has led to an increase in the need for clean water, as well as extensive research to achieve a beneficial way to remove pollutants. Photo catalyst is a green method widely used in the field of water purification. Because different types of pollutants can be completely decomposed by photocatalytic active light-emitting diodes under UV light. ZnO nanostructures with different morphologies have attracted much attention to photocatalytic applications in the environment and energy fields. Among the various forms of nanofibers with outstanding features such as high surface area, convenient reusability and higher yields, but due to the wide bandgap of zinc oxide, UV is used as a source of radiation, which is a major factor limiting the use of ZnO photocatalytic nanofibers. Photocatalytic reactions under visible light can be achieved by doping of ZnO with an appropriate element. In this study, two suitable elements, silver (Ag) and multiwall carbon nanotubes (MWCNTs) were used to reduce electron-hole recombination and increase light absorption, which would increase photocatalytic efficiency under visible light. Ag-ZnO / CNT nanofiber was synthesized by polymeric PVA electrospinning method, containing metal precursors and appropriate amounts of Ag and CNT nanoparticles. Then the obtained nanofibers were calcinated under the furnace conditio the temperature was rate 3?C / min, the temperature of 600?C, and the time of calcine 5h. Nanofibers were characterized by infrared spectroscopy (FTIR), scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) tests. The results of FTIR and XRD tests confirmed the formation of ZnO crystals and the presence of Ag and CNT particles after calcination treatment. Also, FE-SEM images show nanofibers morphologies in different calcination condition, indicating the most important effect of temperature and temperature rate on the formation of nanofibers. With the addition of Ag and CNT particles to pure nanofiber ZnO, the dye degradation efficiency under visible light exposure increased from 48.86% to 67.32% and 98.81%, respectively. The effects are factors such as radiation source, pH and amount of photo catalyst on the dye degradation process were also investigated. Also, COD was measured and results show the suitable pH for the dye degradation process was pH = 7. The results confirm that ZnO based on Ag / CNT nanoparticles has prominent photocatalytic activity.