The invention discloses a small-radius bending and edge-rolling method for a magnesium alloy sheet. The small-radius bending and edge-rolling method comprises the following steps that hot rough rolling, hot medium rolling and hot fine rolling are conducted on the magnesium alloy in sequence under the corresponding temperature conditions, heat treatment is conducted on a thin sheet, then the thin sheet is water-cooled to the room temperature, heating treatment is conducted on the rolled edge of the thin sheet, the thin sheet is put into a cold die for molding and quenching, and bending and edgerolling of the magnesium alloy sheet are completed. By means of the method, heating can be conducted on the rolled edge by adopting various heating manners, edge rolling and bending are conducted bybeing combined with a heat punching molding process, the edge rolling problem of the magnesium alloy sheet can be significantly improved, and the high surface quality and mechanical properties are achieved.