An anti-theft apparatus for a mobile device, the apparatus comprising: a base attached to a back surface of a mobile device; a connecting terminal provided in a rear side of the base and connected to an access port of the mobile device; a separation sensor provided in a front side of the base, the separation sensor sensing separation of the mobile device from the base; and a distance control unit including: an elevating block to which the connecting terminal is mounted, and a distance control pin unit moving the elevating block upward and downward so that the distance control unit controls a distance between the base and the connecting terminal, wherein; the distance control pin unit includes: a screw pin screw-coupled to the elevating block, and an operation pin passing the cover of the base and coupled to the screw pin, whereby a step is formed along an edge of a first through hole of the base, a seating protrusion is formed along an edge of the operation pin and engaged with the step to be seated thereon, and a stopper is provided in the base, wherein the stopper presses the edge of an upper surface of the operation pin, thereby preventing the operation pin from leaving a predetermined position thereof and allowing the distance control pin unit to rotate in a forward direction or a reverse direction at a predetermined position thereof, wherein the distance control unit further includes an elastic plate of which a lower side formed in a U-shape is inserted into and coupled to the elevating block by a male and female coupling method, and an upper side is inclined diagonally and elastically supports an inner wall of an upper side of a cover of the base, thereby continuously pushing the elevating block toward the distance control pin unit, and allowing the elevating block to move upward or downward without shaking at a predetermined position. a base attached to a back surface of a mobile device; a connecting terminal provided in a rear side of the base and connected to an access port of the mobile device; a separation sensor provided in a front side of the base, the separation sensor sensing separation of the mobile device from the base; and a distance control unit including: an elevating block to which the connecting terminal is mounted, and a distance control pin unit moving the elevating block upward and downward so that the distance control unit controls a distance between the base and the connecting terminal, wherein; the distance control pin unit includes: a screw pin screw-coupled to the elevating block, and an operation pin passing the cover of the base and coupled to the screw pin, whereby a step is formed along an edge of a first through hole of the base, a seating protrusion is formed along an edge of the operation pin and engaged with the step to be seated thereon, and a stopper is provided in the base, wherein the stopper presses the edge of an upper surface of the operation pin, thereby preventing the operation pin from leaving a predetermined position thereof and allowing the distance control pin unit to rotate in a forward direction or a reverse direction at a predetermined position thereof, wherein the distance control unit further includes an elastic plate of which a lower side formed in a U-shape is inserted into and coupled to the elevating block by a male and female coupling method, and an upper side is inclined diagonally and elastically supports an inner wall of an upper side of a cover of the base, thereby continuously pushing the elevating block toward the distance control pin unit, and allowing the elevating block to move upward or downward without shaking at a predetermined position.