Abstract: The testing of the blended ratio of cashmere/wool yarns is mainly depended on manual operation,which is low in speed and accuracy.An object extraction method based on the HSV color model was proposed,which could be used for testing the blended ratio of cashmere/wool yarns.First both the cashmere and wool that have some color information were withdrawn from the background.Then,according to their different shapes,the target could be separated by using the erosion and dilation techniques.Finally test the blended ratio of cashmere/wool yarn.Findings demonstrate that this technique is practical in testing the blended ratio of cashmere/wool yarns.