In order to shorten the exposure time of the X-ray photography and obtain a clear image, the X-ray tube should produce a higher density X-ray in a very short time. For this reason, the power of the X-ray tube must be increased. However, the energy supplied to the tube is converted to X-ray with a very low power, and more than 99% of the energy is converted into heat energy and dissipated on the anode, causing the anode temperature to rise rapidly. In the fixed anode X-ray tube, since the heat is concentrated at the point of focus, the anode is easily overheated and melted. However, in the rotating anode X-ray tube, due to the constant rotation of the anode, so that the heat distribution in a ring area, greatly increasing the heat dissipation area, significantly reducing the anode temperature; live at the same temperature can greatly improve the X-ray tube power. Rotation of the anode X-ray tube production, so that the development of diagnostic X-ray tube appeared a leap forward, a strong impetus to the development of medical diagnostic technology.