The traditional binocular endoscope can only provide clear images, and can not carry out threedimensional measurement/reconstruction. In this paper, a binocular endoscope system based on the stereo vision principle is proposed to realize three-dimensional measurement/reconstruction, and a speckle threedimensional reconstruction system based on a binocular endoscope is developed. To improve the calibration accuracy and 3D reconstruction quality of the system, a high-precision binocular endoscope calibration parameters optimization method and a stereo correction algorithm based on twice rotation of the optical axis are proposed in this paper. The measurement system consists of a structured light illumination system and a binocular endoscope. Firstly, the image with random speckle is characterized by projection through the structured light illumination system, and then the epipolar correction and stereo matching are carried out after stereo imaging by the binocular endoscope. Finally, the three-dimensional information of the object is reconstructed according to the principle of triangulation. The experimental results show that compared with the traditional method, the measurement accuracy of standard bodies such as cone and ball is significantly improved.