Water polluted by organic dyes is a serious environmental problem. In response to this, the aim of this research is to degrade dye wastewater using a modified photocatalyst. Since sunlight only has less than 5% UV energy, for a general photocatalyst, using sunlight for excitation to decompose organic pollutants is not an effective way. Therefore, we manufactured the modified photocatalyst by zirconium dioxide, graphene oxide, and titanium dioxide. This was to better improve the photo-degradation efficiency for the degradation of organic pollutants. The modified photocatalyst was analyzed by X-ray diffractometer (XRD), Fourier-transform infrared spectroscopy (FT-IR), Raman spectroscopy (Raman), Scanning Electron Microscope (SEM), and Energy-dispersive X-ray spectroscopy (EDS). The results demonstrated that the modified photocatalyst can be activated by the absorption of visible light. Additionally, the band gap of the modified photocatalyst would decrease. The photodegradation percentage of the modified photocatalyst under visible light (Philips TL-D 8W/865 fluorescent tube) for 4 h reached up to 49.92%. At the third test after ultrasonic washing for the cyclic test, the photodegradation percentage of the modified photocatalyst could still maintain at 47.71%. This indicates that the modified photocatalyst has good stability and reusability, and so this can be reused in this regard.