Disclosed herein are a tomosynthesis system for digital X-ray imaging and a method of controlling the tomosynthesis system. The tomosynthesis system includes an X-ray source, a detector, and a terminal. The X-ray source continuously moves during a scan period, and maintains a uniform X-ray focus in each capture section in which capture is performed by adjusting the direction of an emitted electron beam. The detector detects an image of X-rays having passed through an area of interest of an object in the capture section. The terminal controls the adjustment of the direction of the electron beam, creates a three-dimensional (3D) X-ray image by synthesizing detected X-ray images, and then displays the 3D X-ray image.