A System on a Programmable Chip(SoPC) based fast dehazing system for video image is proposed, aiming at the problems of high time-complexity and difficulties in real-time processing for existing algorithms. Firstly, the hardware structure and software process of the SoPC based platform are introduced. And then the algorithms of dark channel prior and guided filter are studied. At last, the algorithms are transplanted to the proposed platform. The experiment demonstrates that the system can meet the requirement of the real-time dehazing effectively，and restored images are pretty clear with fine contrast and natural color.