This paper describes an X-ray three-dimensional image display apparatus based on the principle of the binocular parallax and the method of optics and electronics. It can transform invisible X-ray image into visible three-dimensional image.The X-ray source used in this work consists of two triode X-ray tubes, and a plumbicon camera with high sensibility and low lag and an image intensifier are used as TV camera system. By means of processing the electronic image, we have succesfully obtained clear and extremely low X-ray dose three-dimensional image.After a brief description of the basic principle, our emphasis is laid on the analytical method of stereoscopic depth of the three-dimensional image and method of processing of how to get a stereoscopic image.The apparatus is very valuable for practical use in research works on physics, biology and medicine.