Optical coherence tomography (OCT) is a new imaging technique after X-ray imaging, magnetic resonance imaging, ultrasonic imaging and so on, and its characteristic of can be optical fiber make it easy to combine with medical electronic endoscope. OCT endoscope technology can realize the high rate, high resolution, non-destructive and real-time imaging of human internal organs. The classification and basic principles of OCT as well as some important parameters of OCT technology including the probing depth and axial resolution are mainly introduced. Some recent research achievements and development of OCT endoscope scanning probes are discussed. The influences of light source on OCT endoscope are mostly analyzed. The main application of OCT endoscope is summarized.