Abstract: In order to improve image acquisition rate and axial resolution of optical coherence tomography at lower cost, spectral-domain optical coherence tomography (SD-OCT) was studied both theoretically and experimentally. Some basic data and images were obtained based on the measurement of film workpieces. The results show that the images of their internal structure are visible clearly and SD-OCT under white light illumination is feasible and enables to realize the real-time 3-D imaging reconstructions of internal structure of engineering and biological materials.