Abstract: Provided are a coated cobalt powder and a preparation method thereof, the coated cobalt powder consisting of cobalt powder, and paraffin wax, polyethylene glycol or polyethylene coated on the outer surface of the cobalt powder. Using the coated cobalt powder to replace traditional cobalt powder as the raw material for preparing hard alloys, the dusts generated during production can be reduced, and the environment in a production shop can be improved; simultaneously, the paraffin wax, the polyethylene glycol or the polyethylene coated on the surface of the cobalt powder can effectively prevent the cobalt powder from being oxidized by the oxygen or water vapor in the air, thus improving the quality of the cobalt powder. The preparation process of the coated cobalt powder is free from contamination and the coated cobalt powder is suitable for industrialized production.