With outstanding features of high resolution and high acquisition rate, line-scan imaging holds great potentials for high-speed applications. This paper presents a stereo line-scan system for 3D shape measurement of fast moving objects. The principle and key technologies are addressed. The system setup and 3D imaging model are introduced first and the stereo matching scheme and calibration approach are described subsequently. The system is verified by experiments. The results demonstrate the validity and accuracy of the proposed system.