A one-touch bevel cut depth controller for a beveling machine comprising: a beveling machine body, wherein a spline shaft connection unit is positioned at an upper center part of the beveling machine body and a cutter operation unit is positioned at a lower center part thereof, and the spline shaft connection unit and the cutter operation unit are operatively connected to each other; a movable spline shaft vertically movably connected to the spline shaft connection unit by a screw thread, wherein a first spline is positioned around an upper outer circumference of the movable spline shaft; a bevel cut depth controlling unit, wherein a second spline surrounding an outside of the movable spline shaft is positioned around an inner circumference of the bevel cut depth controlling unit, which is able to move by a vertical sliding motion and is connected to the first spline; an elastic spring; a plurality of securing openings formed at a lower part of the bevel cut depth controlling unit in a circumferential direction; a plurality of location setting pins positioned at an upper outer part of the spline shaft connection unit in a circumferential direction and selectively fit into the securing openings, to fix the location of the bevel cut depth controlling unit and maintain the locking thereof; a sleeve shaft rotatably installed in the movable spline shaft; and a cutter shaft rotatably installed, characterised in that: - the one-touch bevel cut depth controller further comprises a spring housing inserted into a guide groove formed at an upper part of the bevel cut depth controlling unit and integrally attached to an upper end of the movable spline shaft; - the elastic spring is interposed between an inner surface of the spring housing and the guide groove of the bevel cut depth controlling unit; and - the cutter shaft is rotatably installed in a bearing housing installed to be inserted into a lower part of the cutter operation unit, wherein the cutter shaft is integrally connected to a lower end of the sleeve shaft so that the cutter shaft and the sleeve shaft operatively rotate and vertically move together. a beveling machine body, wherein a spline shaft connection unit is positioned at an upper center part of the beveling machine body and a cutter operation unit is positioned at a lower center part thereof, and the spline shaft connection unit and the cutter operation unit are operatively connected to each other; a movable spline shaft vertically movably connected to the spline shaft connection unit by a screw thread, wherein a first spline is positioned around an upper outer circumference of the movable spline shaft; a bevel cut depth controlling unit, wherein a second spline surrounding an outside of the movable spline shaft is positioned around an inner circumference of the bevel cut depth controlling unit, which is able to move by a vertical sliding motion and is connected to the first spline; an elastic spring; a plurality of securing openings formed at a lower part of the bevel cut depth controlling unit in a circumferential direction; a plurality of location setting pins positioned at an upper outer part of the spline shaft connection unit in a circumferential direction and selectively fit into the securing openings, to fix the location of the bevel cut depth controlling unit and maintain the locking thereof; a sleeve shaft rotatably installed in the movable spline shaft; and a cutter shaft rotatably installed, - the one-touch bevel cut depth controller further comprises a spring housing inserted into a guide groove formed at an upper part of the bevel cut depth controlling unit and integrally attached to an upper end of the movable spline shaft; - the elastic spring is interposed between an inner surface of the spring housing and the guide groove of the bevel cut depth controlling unit; and - the cutter shaft is rotatably installed in a bearing housing installed to be inserted into a lower part of the cutter operation unit, wherein the cutter shaft is integrally connected to a lower end of the sleeve shaft so that the cutter shaft and the sleeve shaft operatively rotate and vertically move together.