Abstract: The preparation of the tungsten foil for equation of state(EOS) target was studied by electropolishing in sulfuric acid-methanol. The anodic polarization curve of the tungsten foil was analyzed, and the surface topography, grain orientation, density and thickness uniformity were tested. The tungsten foil was prepared with high surface quality (RMS roughness less than 50 nm) and thickness uniformity beyond 99%, and could keep the density of raw materials. This foil could satisfy the requirement of laser driven materials for the research of high temperature and pressure EOS. Thus electropolishing is a significant method for preparating the foil which can fulfill the requirement of EOS target.