The invention relates to a preparation method of high carbon metalized pellet for waste water treatment, belonging to a technical field of metallurgical products, which is used to solve the problem that the surface passivation is easy to be generated in the material filtering in iron carbon by the method of electrolysis so as to affect waste water treatment effect. The invention is characterized in that: the high carbon metalized pellet contains single iron, activated carbon and few impurities, wherein the particle diameter of the single iron is less than 0.2mm, the activated carbon is a pore structure, the specific surface area reaches 500-800 square meter per gram. The method of the invention is composed of raw material preparation, pellet building, drying, reduction and other steps. Experiments evidence: the product in the invention has rich pore structures and huge specific surface, and has strong capability of absorbing contaminations in waste water, moreover the product has higher reaction activities, good osmosis, easy fluidization and no agglomeration. Compared with the conventional electrolysis process, the COD removal ratio of the used filling is improved by above 50 percent under equal time, the waste water with large variable concentration and wide PH value range can be treated.