Abstract: In this paper, Inverse Synthesis Aperture Radar (ISAR) turntable imaging of near field rotating target with large angle is implemented using UWB (Ultra Wide Band) system. With large and discrete rotation angle, and noise pollution considered, the robust Windowing Filtered Spherical Back Projection (WFSBP) algorithm is presented. The compensation of filtering for error resulted from discrete rotation angle is explained geometrically. The Point Spread Function (PSF) is analyzed, which also proves high resolution image can be obtained even transmitting monochromatic signal. Simulation and experiment are conducted, showing the better performance of WFSBP than traditional algorithm. High quality and high resolution image is obtained for the large rotation angle target.