A method of making micro-holes on a metal plate includes: (A) feeding a metal plate on a workbench forward to extend beyond a shearing edge; (B) locating a punching head at a first position, and keeping a working space between the punching head and the workbench; (C) exerting a shearing force towards the workbench by the punching head; (D) bending the metal plate by the shearing force, and forming a plurality of spot-shaped cavities arranged in a row on a second surface; (E) bearing a shearing force on the first surface of the metal plate to form a linear groove; (F) deforming the metal plate by the shearing force to cause the spot-shaped cavities arranged in a row to communicate with the linear groove to form micro-holes; (G) the punching head returning to the first position and moving a working distance to a second position; (H) feeding the metal plate again; (I) the punching head repeating the above steps at the second position; (J) the punching head returning to the second position and then moving back to the first position to complete a processing cycle. The method can produce a maximum of micro-holes on a certain area of the metal plate, which can be used as a sound gobo with an enhanced sound-absorption rate.