Nano-computed tomography (nano-CT) is of great significance for the development of science and technology and the progress of production technology, especially in frontier researches of biomedicine and new material properties. The principle and classification of nano-CT imaging, as well as the implementation, advantages, and disadvantages of the nano-CT system, are reviewed. As for the specified technology detail, the principles, properties, manufacturing bottleneck, and application status of optical components in nano-CT are described. On this basis, the existing problems in nano-CT imaging system and its applications are proposed, and the future development of nano-CT imaging is summarized.