An X-ray imaging device and an X-ray imaging method for obtaining 3D X-ray images of an entire field of view (FOV). The device includes an X-ray source for radiating X-rays to a part of an FOV and an X-ray sensor for detecting the X-rays, which have passed through the part of the FOV. The X-ray sensor has a width narrower than the radius of a smallest circle including a cross section perpendicular to the longitudinal direction of the FOV. A rotating arm supports the X-ray source and the X-ray sensor to face each other with the FOV therebetween. The rotating arm rotates and moves 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.