The present invention relates to a method for preparing a metal powder intended for an additive manufacturing process, of the type that involves scanning a bed of powder by a near-infrared laser beam, characterized in that the method comprises: an initial step for selecting a powder, which has an optical reflectivity of higher than 70% for a wavelength ranging between 800 and 1500 nm; then a step for treating said powder, which is different from particle grafting, and which induces a physical and/or chemical surface modification of the grains of said powder, making it possible to lower its optical reflectivity, at the given wavelength. The invention also relates to the use of such a powder, the grains having, after treatment, a median grain size d50 of between 5 and 50 μm.