The production, sale and use of radiation devices have been included in environmental protection supervision, and the radiation safety licenses need to be handled. With the development of society and economy, the radiation devices are widely used in the medical care, safety inspection, electronic devices and pressure vessel detection etc. The X-ray tube is the source of X-rays production in the X-ray equipment, but its administrations have some problems during the manufacture, sale and use. This paper introduces the working principle, structure and classification of X-ray tubes. The suggestions are proposed based on the problems of radiation safety supervision in X-ray tube.