Abstract: For high reflective surface and small fillet structural workpiece, traditional optical measurement methods and equipment are difficult to meet engineering requirements. A spherical center offset measurement method was proposed based on the blue light scanner.We made sand-treated steel balls adhere to the workpiece and scanned the steel balls by using blue light scanner.Then we fitted the sphere center of the point cloud and offset the sphere radius along the normal direction of the workpiece surface to obtain the actual workpiece point.The standard cylinder's fitting-diameter-deviation is 0.000 2 mm and the measurement accuracy is less than 0.03 mm by using the method. The result proves the feasibility of the method.Taking a section of polishing blade which fillet radius of inlet and exhaust edge is less than 0.1 mm as an example, the measurement accuracy is within 0.03 mm.This method is not affected by the workpiece material and it has great significance for the measurement of the workpiece which has high reflective surface and small fillet feature.