Aiming at the characteristics of the airborne forward-squint SAR imaging, a high-performance SAR real-time processing system is established in this paper. Firstly, in order to realize range cell migration correction (RCMC) accurately and range-azimuth decoupling in forward-squint SAR imaging, a high-precision SAR imaging algorithm is used in this system, namely nolinear chirp scaling(NCS) algorithm. Secondly, the motion of airborne platform is unstable, so the weighted phase gradient autofocus (WPGA) algorithm is used for motion compensation. Finally, a real-time signal processor is designed which is based on the TMS320C6678 multi-core DSPs issued by TI. The processor satisfied the demands of SAR real-time imaging because of its powerful processing performance and high-speed data transmission ability.