Abstract: Aiming at the problem that existing imaging algorithms of forward-looking synthetic aperture radar（SAR）which is all based on the situation that the platform is moving in low velocity，and thus can not be applied to platform of high velocity，taking airborne forward-looking SAR system using single transmitting and multiple receiving antennas as the research object，the model of spatial geometry and echo signal of high velocity forward-looking SAR is analyzed and the digital beam sharpening（DBS）imaging algorithm which is suitable for high velocity forward-looking SAR is proposed.Meanwhile，in order to solve the imaging problem brought by high velocity，corresponding range migration correction scheme is proposed，and imaging quality of DBS algorithm is remarkably improved after correction.Finally，the raw echo data of an array of point targets is simulated，and the focused images are obtained using the proposed algorithm.Imaging results demonstrate the validity of the algorithm.