The invention provides a method for improving contact resistance uniformity. The method comprises the steps of: providing a wafer with an interlayer dielectric layer; forming a hard mask layer on the interlayer dielectric layer; and polishing the hard mask layer and the interlayer dielectric layer until the interlayer dielectric layer has the desired thickness. Due to the protection of the hard mask layer, the thin part of the interlayer dielectric layer can not be worn by a polishing fluid and a polishing pad, so that the obtained interlayer dielectric layer has uniform thickness, thereby obtaining uniform contact resistance distribution. The method provided by the invention is simple and convenient and has the advantage of low process cost.