A 3D multifunctional device in which a 3D printer and a 3D scanner are combined and a method for operating the device. The 3D multifunctional device includes a printing unit that includes a nozzle for ejecting material for 3D printing, a scanning unit that includes a light radiation module for radiating light to an object to be scanned and a camera for capturing an image of the object, a head unit for moving the printing unit and the scanning unit in X-axis and Y-axis directions, a bed plate on which the object to be scanned is located or the ejected material is deposited, the bed plate moving in a Z-axis direction, and a control unit for setting a function by selecting 3D scanning or 3D printing, controlling the scanning unit or the printing unit, and controlling the movements of the head unit and bed plate.