Rhodamine B can be degraded using Prussian blue/g-C3N4 as a photo-Fenton-like reagent under visible light. In this research, factors affecting the photocatalytic degradation of rhodamine B,including initial rhodamine B concentration, H2O2 dosage, light source intensity, and light source, were investigated. The results showed that the degradation of rhodamine B occurred with a suitable concentration of H2O2 (0,02 mol/L) and achieved the highest efficiency of 93,93% after 60 minutes under visible light irradiation. Our research results in a breakthrough in the field of photo-Fenton and greatly advances the practical utility of this method for environmental applications.