The shaft that is of spiral blades rotates in the fixed groove, and then feeds the bulky materials into the groove, which is hampered by the friction resistance of the walls of groove whilst turning with the spiral blades inside the groove. In the process of this running, the spiral blades push materials to move along the axial direction, and then make materials output from the appropriate opening underneath the groove or from the end of the groove. The LS screw conveyor is of these advantages, such as: simple structure, loading and unloading materials from multiple points in the middle is allowable, operating safely and conveniently, good sealing performance and environmental protection.