Abstract: To overcome the shortcomings of manual operation and improve the efficiency and accuracy of measurement, the actual length of the yarn was measured by yarn configuration scanning and the weaving shrinkage was computed, which was compared with that by traditional manual measurement. In the experiment, combining Otsu basic principle with computer image processing technology, binarization processing was carried out. Then the extracted data from the image was fitted by using Matlab software. Finally, the curve length of the yarn in the scanning image was calculated by using definite integral method. The results demonstrated that the measurement results of the two methods are in good agreement, and the yarn configuration scanning method is faster, simpler and more accurate.