The hard tissue of fish, especially the skeleton, is the tissue that supports fish body and protects its internal organs. The characteristic detection and analysis of the hard tissue is the data basis for studying fish swimming motion, fish anatomy, fish body modeling and so on. With the development of X-ray technology and the wide application of domestic equipment, the cost of instruments and equipment has been significantly reduced, which makes the application of X-ray in fishery research and automatic production possible. The basic principle of X-ray technology and its application in the detection of fish body tissues were first introduced. The application of X-ray technology in the field of fishery was mainly divided into nondestructive detection of fish tissues and organs, and identification of trace elements in fish body. X-ray technologies, including photography, digital imaging, diffraction and X-ray absorption spectroscopy, were introduced respectively. Then, their applications in the modeling of fish body tissues and organs, fish skeleton detection, fish fossil research, otolith analysis and trace element detection of fish body were reviewed, and problems existing in the application of X-ray in the field of fishery were summarized. Finally, the fishery application of X-ray was prospected.