A preparation method of a separator for an electrochemical device, and a preparation apparatus therefor are provided. The preparation method includes: supplying a porous separator substrate; coating one surface of the porous separator substrate with a first coating agent and a second coating agent by means of a first coating part of a die coating method that includes a first roller; coating the other surface of the porous separator substrate with a third coating agent by means of a second coating part of a roll coating method that includes a second roller; and forming a first coating layer, a second coating layer and a third coating layer by drying the porous separator substrate coated with the first coating agent, the second coating agent and the third coating agent coated thereon, in which a pattern is formed on the surface of the second roller.