Abstract: The raw silk embedding slice was changed to HSI color model from RGB color model,after that the raw silk′s cross-section with some color was extracted from the background image based on HSI color model,and the processed color image was changed to gray image.The image of raw silk′s cross-section was turned to binary image through edge detecting,then the binary image of raw silk′s cross section was processed with image dilation and erosion after analyzing the shape and the size of it,and the whole raw silk′s cross-section was got.Finally the characteristic parameters of raw silk′s cross-section were gained by using the image matrix processing.The results indicted that this method can gain the characteristic parameters of raw silk′s cross-section exactly.