To achieve swift, precise, and non-destructive detection of ball screw raceway's normal section, a measuring system based on an optical micrometer is developed. Initially, the detection device is crafted following the principle of measuring the ball screw raceway's normal section. The original data processing algorithm for the raceway's normal section is then refined, introducing the angle division arc method and arc data homogenization technique. Subsequently, potential errors from sensor installation, the horizontal moving platform's straightness, and sensor inaccuracies within the detection device are examined and compensated for. The detection system's accuracy, comprising the device and the enhanced algorithm, is validated through experimental tests. These tests reveal that with the algorithm's optimization, the normal section parameters of the raceway measured by the system show improved convergence as the divided arc angle increases. Post-optimization, the maximum measured values for arc radius and contact angle, along with the manufacturer's error margins, are 3.6 μm and 19′31″, respectively, marking enhancement rates of 64.36% and 53.46% over pre-optimization. Furthermore, the maximum standard deviation values for the measured arc radius and contact angle are 1.56 μm and 2′41″, respectively, with enhancement rates of 22.77% and 56.67%. Class A uncertainty for measured arc radius and contact angle dropped to 0.63 μm and 1′6″, respectively, a reduction of 56% and 70% compared to before the algorithm's optimization. The detection system's accuracy and repeatability for the raceway's normal cross-section meet the measurement standards.