A lampshade module to be combined on a lamp to change the light projection angle of the lamp includes a lens holder having lens holes and first buckle portions at the hole wall of each lens hole for holding down the inserted lens, and a plurality of lenses each having a light entrance surface corresponding to the bottom end of one respective lens hole and an opposing light-emitting surface. The light entrance surface is a convex arc surface, and the arc of the convex arc surface is set according to the light projection angle required. In this way, the lenses with the appropriate projection angles can be selected and assembled in the lens holes, and then the lens holder can be assembled in the lamp.