Optical Coherence Tomography (OCT) has been widely used in medicine,biology,materials and other fields.Developing a lower cost and higher imaging speed OCT system has become an important trend in OCT technology development due to its non contact,non invasive and high resolution advantages.A line scanning frequency domain OCT imaging system based on LED illumination is proposed in this paper,and its principle introduced in details.Through systematic structure designs,theoretical calculations and experimental verification are performed.The experimental results show that the proposed system reduces cost and has faster imaging speed compared with traditional methods,and has potential application value.