A high-performance photocatalyst should be superior not only in light absorption and charge transfer but also surface catalytic reaction. Here we report a green and simple strategy for evenly decorating Ag3PO4 particles using magnetic NiFe2O4 nanoparticles (NPs). The NiFe2O4 NPs could act as a magnetic support material for recycling the photocatalysts, as well as in situ catalytically decompose the H2O2 produced on the surface of Ag3PO4 into O-2 center dot(-) and center dot OH radicals via a photo-Fenton process. The catalytic decomposition of H2O2 could produce strong oxidative capacity O-2 center dot(-) and center dot OH radicals for the organic pollutants degradation and reduce host semiconductor holes (h((Ag3PO4))(+)) consumption by these produced H2O2. Thus, the photocatalytic activities of Ag3PO4@NiFe2O4 composites were greatly enhanced. Taking the photocatalytic degradation of Methyl orange (MO), hardly decomposed colorless phenol compounds bisphenol A (BPA) and killing Escherichia coli (E. coli.) as mode photocatalytic reactions, this system exhibited superior photocatalytic performances than that of pristine Ag3PO4. Electron spin resonance (ESR) spectroscopy and sacrificial-reagent incorporated photocatalytic characterizations indicated that the in situ eliminating/active decomposition of H2O2 produced by Ag3PO4 was the main reason for the enhanced photocatalytic activities.