Abstract: To solve the problem of large scale three-dimensional (3D) measurement with high accuracy, a new binocular stereo vision inspection system was presented. By projecting variable period fringes, the surface with different curvature was coded with phase. The stereo matching points were determined using phase matching technique, so that dense 3D coordinate points could be calculated by the intrinsic and extrinsic parameters of the calibrated cameras. In order to solve the problem of small measurement field of sensor unit, the vision sensor scanned the whole surface of a large object under a step motor’s control, then quaternion was used to realize 3D registration. The sensor’s standard deviation in length measurement is 36 μm, and the relative error of angular measurement is 0.2% compared with the CMM(coordinate measuring machine). The 3D integration of a large object (360 mm×360 mm) is given correctly.The vision system is of great engineering value in large 3D non-contact online measurement with high accuracy.