Abstract: In modern medicine, nuclear scans, Positron Emission Tomography (PET), and Magnetic Resonance Imaging (MRI) technology have been widely used to provide tissue morphology and functional information. However, these technologies have their own shortcomings in resolution or imaging depth. A new optical detection technology based on the principle of low-coherence interference can achieve high-resolution and large-depth imaging at the same time. This technology is called optical coherence tomography (OCT) technology. OCT technology is a non-contact, non-invasive, non-damage imaging technology that combines high longitudinal resolution with high transverse resolution, and can achieve the same effect as biopsy observation. OCT uses a low-energy near-infrared light source as the detection light, combined with non-damaging methods such as microscope heads, hand-held probes or endoscopes, for routine detection, and will not cause damage to biological tissues. At the same time, OCT combined with rapidly developing image acquisition, analysis and processing technology can realize real-time three-dimensional imaging, and extract useful information for diagnosis for quantitative analysis, which provides convenience for doctors' diagnosis. This review focuses on the classic OCT imaging technology and its related medical application technologies, such as SD-OCT, SS-OCT, aOCT, PS-OCT and D-OCT, in the detection of diseases of the respiratory system, oral cavity, brain tissue, kidney and other major organs in the application.