In this study, a natural optical fiber illumination system is proposed based on a lightguide plate concentrator to maximize the utilization of solar energy. Further, the energy in the invisible band is converted into electricity using the spectral module for driving the LED array in the compensation system. Thus, a stable lighting energy output can be obtained under various weather conditions. A simulation software is used for light tracing, and the obtained results denote that approximately 60% of the total luminous flux in case of an indoor area of 100 m ² and lighting for 12 h can be supplied by solar energy. Subsequently, a lightguide plate concentrator system is developed and tested via concentration experiments for developing a natural optical fiber illumination system to further verify the feasibility and accuracy of the proposed system. When the number of light collection modules increase from 10 to 100, the optical efficiency of the concentrators decreases from 83.6% to 65.1%. The variation trend of the output illuminance of the optical fiber is consistent with the input irradiance of the solar during the biaxial tracking test for optical fiber illumination system at outdoor, indicating the good light gathering performance of the proposed system.