Abstract: The twice extrusion technology was employed to make alum-free potato noodles with potato starch used as main material and no alum added.The effects of first and second extrusion temperature and water feed rate on the sensory evaluation scores and quality characteristics ( the rate of broken noodles, cooking loss, swelling degree, rigidity) were investigated by single factor experiments and orthogonal tests.The results showed that the best quality of potato noodles, which owned good sensory quality and cooking properties, was obtained with first extrusion temperature at 90℃, second extrusion temperature at 90℃ and water feed rate at 32%.Compared with traditional methods, using the twice extrusion technology to produce alum- free potato noodles was featured by simplified process, time-saving, energy- saving, water- saving and stable product quality, which was suitable for continuous and large-scale production.