Abstract: A 3D measurement system using line-structured-light sensor is proposed for the measurement of complicated deep-hole profile, which has the characteristics of both rapidity and high precision. System configuration, measurement principle and mathematical model along with the algorithm were presented. Combining morphological stripe-thinning algorithm with gray-scale barycenter algorithm, the stripe center locus could be extracted with accuracy in sub-pixel lever. Experiments were carried out to measure a complicated profile deep-hole with the length of 70 mm and the diameter of 130.0 mm. The results show that the masculine diameter measurement error is ±32 μm, while the feminine diameter measurement error is ±54 μm.