The invention relates to a preparation method for a ternary copper powder catalyst used for synthesis of methylchlorosilane. The method comprises the following steps preparing ultrafine CuO powder through ball milling; then mixing the ultrafine CuO powder with copper powder; uniformly pressing and embedding or attaching the ultrafine CuO powder to the surface of the copper powder; and carrying out gradient oxidation in a rotary tube furnace, ball milling and the like so as to prepare the ternary copper powder catalyst. According to the invention, ultrafine CuO is uniformly pressed and embedded into or attached onto the surface of the copper powder and continuous gradient oxidation in the rotary tube furnace are cooperatively used, so the problems of easy caking, nonuniform oxidation and uneasy regulation of the contents of Cu-Cu2O-CuO ternary components in the process of partial oxidation of the copper powder are overcome, the preparation method has the advantages of simple process, easy operation and low cost, and the prepared catalyst has high activity and selectivity.