The paper proposes a stereo vision coordinate measurement system based on optical probe with the function of measuring and calibrating. The system adopts the probe as the imaging object and obtains the three-dimensional (3D) coordinate of the measured object by the images of the optical features on the optical probe got by the two cameras arbitrarily placed. During the measuring process, the extrinsic calibration parameters of the two cameras are calibrat calibrated termly with the measurement data. The key techniques, including the design of the calibration patterns and calibration algorithms of the camera intrinsic parameters and the extrinsic parameters online calibration of two cameras, and stereo vision measurement modeling, are studied. The corresponding schemes to reduce the effect of camera extrinsic and intrinsic parameters calibration and measurement modeling and improve precision are presented. The experimental results show the maximum error is 0.11 mm.