In this paper, a new fast center extraction algorithm of structured light stripe is proposed, which can extract the center of structured light stripe quickly under complex motion blur. This paper analyzes the causes of blurred motion imaging of line structured light and the gray value distribution law of the light stripe section in the image, and designs a P-tile threshold segmentation algorithm based on the theoretical light stripe imaging width, which solves the difficulty of extracting the light stripe area caused by the different light stripe imaging width and irregular brightness change in the case of motion blur. According to the characteristics of the light stripe image, the positioning speed of the light stripe is improved by the improved region growth algorithm, and the center of the structured light stripe is extracted according to the gray value distribution of the light stripe section. The experimental results show that the improved P-tile threshold segmentation algorithm is more effective than the extreme value method and Otsu method when segmenting the optical stripe region under motion blur. Our center extraction method provides faster speed and better precision, and has practical value in high-speed industrial measurement of structured light.