A Linnik interference microscope-based full-field optical coherence tomography (FF-OCT) system is developed to obtain high-quality optical sectional images. Compared with other FF-OCT systems illuminated with optical fiber (OF) bundle, the improved Khler illumination arrangement with a halogen lamp is used in the proposed FF-OCT system. A tomographic image of an Intel Pentium 4 chip is retrieved from four sequential phase-shifted interferograms by using a four-step algorithm. The experimental results confirm the feasibility of the proposed imaging system. The proposed improved Khler illumination-based FF-OCT system is characterized by its use of simple elements and lower cost, providing a simple and convenient method for high-resolution OCT imaging.