The laser speckles based structured light technique performs 3D reconstruction with a single shot, which makes it one of the most important ways to achieve dynamic measurement. However, it is inaccurate, which makes it difficult to meet the needs of accurate measurement. This paper develops a low-cost and miniature 3D vision system for dynamic depth recovery. A high-precision calibration optimization method for binocular camera and an optimal stereo image correction method based on a two-step rotation are proposed, which improves the calibration and measurement accuracy of system’s parameters. Our system consists of a miniature projector and two cameras. A single pattern with pseudo-random speckles is projected onto the surface of the target object and imaged by a stereo camera. Another single pattern with pseudo-random spots is projected onto the surface of the target object. The depth and contour information of the target is recovered by using the feature matching and triangulation principle. After testing, the measurement accuracy of the proposed structured light system is significantly higher than that of the traditional calibration method under the condition of using optimized calibration and rectification parameters. Compared with traditional method, the sphere reconstruction error of the proposed system is 1.05 mm, and the accuracy has been increased by 52.38%. The cylinder reconstruction error is 1.61 mm, and the accuracy has been increased by 63.98%.