The present invention relates to an X-ray imaging device and an X-ray imaging method for obtaining three-dimensional X-ray images of the entire field of view (FOV) by means of an X-ray sensor having a small width narrower than the radius of a smallest circle including the FOV. In particular, the present invention provides an X-ray imaging device and an X-ray imaging method using same, the device comprising: an X-ray source for radiating X-rays to a part of an FOV; an X-ray sensor for detecting the X-rays, which have passed through the part of the FOV, the X-ray sensor showing a width narrower than the radius of a smallest circle including a cross section perpendicular to the longitudinal direction of the FOV; and a rotating arm for supporting the X-ray source and the X-ray sensor to face each other with the FOV therebetween, the rotating arm rotating and moving about an axis of rotation between the X-ray source and the X-ray sensor so that the X-rays are radiated to the entire area of the FOV in various directions of the FOV.