In this work, controlling the pH of the solution was 8, which ensure that the carbonate exists in the form of bicarbonate. The bicarbonate were decomposed carbonate by heating. The carbonate and zinc ions producted zinc carbonate precipitation, zinc carbonate were decomposed ZnO by calcination. Nanometer ZnO were preparated by homogeneous precipitation. Samples were characterized by Xray diffraction(XRD),scanning electron microscopy(SEM),UV spectroscopy. The rhodamine B(RhB) was aim of degradation.The photocatalytic activity of the samples was evaluated by the photocatalyst of rhodamine B(RhB) under UV light irradiation.It was studied on effects of catalyst dosage, pH and H2O2 dosage on photocatalytic time. The experimental results show 100 mL RhB was completely photocatalized in 130 min under adding the mass of calalyst was 24 mg ,pH was 4 and the volue of H2O2 was 2 mL.