High visible-light photocatalytic activity silver phosphate (Ag₃PO₄) was successfully prepared via a facile water bath method. Scanning electron microscopy (SEM) images show that the products undergo three morphological changes during the reaction process, and the final product has uniform cubic-relievo morphology with an average particle size of about 1.6 μm. X-ray diffraction (XRD) patterns indicate that the samples are body-center cubic structure. In addition, the high resolution transmission electron microscopy (HRTEM) images show that several crystal facets are located in the surfaces of cubic-relievo Ag₃PO₄. UV-Vis absorption and photoluminescence (PL) spectra demonstrate that the products possess high visible-light responsive performance and weak PL emission intensity. The cubic-relievo Ag₃PO₄ exhibits significantly higher catalytic performance when applied on the photodegradation of methyl orange (MO) under visible-light irradiation in comparison to the cubic Ag₃PO₄, intermediate products or commercial nitrided TiO₂ photocatalyst. This work indicates that the photocatalytic performance of the catalyst can be effectively improved by changing its surface structure.