The research on Yingpan shiplock shows that the water-saving ship lock can not only decrease lock’s consuming water, but also lower lock’s working water head so that as to simplify hydraulics technical problems. The relationship between the area of storage pool, steps of storage pool and water-saving efficiency is expounded based on the principle of water-saving ship lock. The ratio of chamber area and storage pool area should not be three times or steps of storage pool not greater than three. The application prospect of water-saving ship lock in inland river navigation is also analyzed.