Optical coherence tomography (OCT) is a nondestructive low-coherence biomedical imaging technology that has developed rapidly in recent years. Owing to its ability to detect the microstructure information of biological tissues, OCT has brought great convenience to biomedical basic and clinical research. OCT has helped to achieve a comparison between dynamic and static structures in ophthalmology, from exploring the initial macular structure to evaluating the retinal and choroidal vascular systems. Additionally, with the development of light sources, the OCT system has become a standard examination method in multiple clinical fields, such as dermatology, gastrointestinal diseases, and cardiovascular diseases. Our article reviews the development of OCT, introduces various types of OCT systems, and compares their imaging principles, performance, advantages, and disadvantages. Finally, the summary and prospective applications of this technology in biomedicine are presented.