Abstract: The natural phosphorite powder was selected to prepare activated phosphorite powder and acidic phosphorite powder by a method of H2SO4 acidification and organic–inorganic agent activation, and several testing instruments including the scan electron-microscope (SEM), the X-ray diffraction (XRD) and the laser granularity, were used to determine the types of phosphorite powder. It was verified that the particle size of more than 90% of the acidic phosphorite powder was less than 4.227 μm, and more than 90% of activated phosphorite powder was less than 220 nm. Additionally, the crystallization of activated phosphorite powder declined, and the surface area increased.