The present disclosure proposes a manufacturing method for a metal grating, a metal grating, and a display device. The manufacturing method comprises: forming a metal layer, an antireflective layer and a deep UV photoresist layer sequentially on a base substrate; etching the deep UV photoresist layer by a photolithography process, so as to form a grating mask pattern; etching the antireflective layer by a dry etching process with the help of the grating mask pattern, so as to form an etch mask pattern identical to the grating mask pattern; peeling off the grating mask pattern; etching the metal layer by a dry etching process with the help of the etch mask pattern, so as to form metal grating strips; and removing the etch mask pattern, thus forming a metal grating.