Portable optical target measurement systems have widespread applications in various fields, including mechanical manufacturing, aerospace, industrial inspection, and clinical medicine. This study aims to address the marker point matching problem in binocular measurement systems. Through image preprocessing and mathematical algorithms, we have successfully achieved robust matching of marker points with uniqueness. We first converted color images to grayscale and applied the Otsu algorithm to adaptively select a global threshold, successfully extracting marker points. Using the nearest neighbor algorithm, we simplified 28 marker points to 7. Then, we employed the k-means clustering algorithm to achieve a second fitting, obtaining marker points located on the central line of the target. With these marker points, we computed key features for describing the target pose, including the direction vector of the target's central line and its angle with respect to the image's x-axis. Finally, we designed different algorithm modules to successfully achieve the robust matching of marker points across 360 degrees of free postures.