Ag@AgSCN nanoparticle was developed as a novel sunlight active photocatalyst. It was prepared by a simple precipitation from AgNO3 and NaSCN, followed by a subsequent photo-reduction deposition of metallic Ag on the surface of AgSCN particles. The photocatalyst was characterized by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM) and UV–vis diffuse reflection spectroscopy (DRS). The as-prepared Ag@AgSCN nanoparticle is efficient and stable for photocatalytic degradation of rhodamine B dye under both the natural sunlight and visible light, without obvious decline of the activity after five repeated cycles. With trapping experiments, the superoxide anion radical (•O2−) involved in the photocatalytic reaction was found to mainly contribute to the elimination of environmental pollutant.