The invention belongs to the technical field of environmental engineering wastewater treatment, and particularly relates to multi-component oxidized micro-electrolysis filler and a preparation method thereof. The multi-component oxidized micro-electrolysis filler is mainly prepared from the following components in percentage by mass: 50-60% of iron, 20-30% of activated carbon, 12-15% of adhesive and 3-5% of catalyst through mixing, wherein iron is iron scrap or iron powder with particle size not more than 80 mesh; and activated carbon is in a powder and has particle size not more than 100 mesh. The preparation method of the multi-component oxidized micro-electrolysis filler comprises uniformly mixing iron, activated carbon, the adhesive and the catalyst according to the ratio, adding water, stirring and aging, then carrying out extrusion molding to obtain molded filler, demolding to obtain a filler blank, after naturally drying, drying, sintering in the absence of air, and cooling thefiller blank to obtain the multi-component oxidized electrolysis filler. According to the invention, the hardening, dead pool, stoppage and other practical problems existing in the use of the traditional micro-electrolysis fillers are solved.