A stereoscopic X-ray imaging apparatus includes: right and left X-ray tubes； a diaphragm unit in which right and left openings are formed through which X-rays radiated by the right and left X-ray tubes pass, respectively； an X-ray sensor on which the X-ray radiated by each of the right and left X-ray tubes is projected； a controller configured to control positions and sizes of the right and left openings； and right and left visible light sources configured to radiate a visible light to the X-ray sensor in the same area as each of the right and left X-ray tubes through each of the right and left openings. Spectra of the visible light emitted by the right and left visible light sources are different from each other.
