GL type grate discharge machine comprises a frame, a drive transmission system, transmission guide wheel, bearing swivel wheels and traction chain closed, tooth harrow and fences around its rotation. In the motor reducer drive, turning the traction chain from bottom to top rotary movement, when tooth harrow drag chain operation to the trash rack on the positive side, the rake teeth that is inserted into the gap in the trash rack as clear fishing action, the the fences are trapped in the debris scraped off the rake. Because tooth harrow teeth rake design double, double teeth was an angle, so that when a tooth is inserted fences clear gap in the fishing, the other with the formation of the teeth is bound to surround the solid debris surrounded, without their lacuna, high removal efficiency and thorough. When operating the machine upper tooth harrow, harrow teeth flip, debris by gravity off on their own container or on the conveyor, the debris away. Meanwhile, in the design of fully take into account: 1. Debris may enter the traction chain, the traction chain stuck, so the design of the closed-end traction chain. 2. Underwater shaft assembly made of stainless steel with nylon bearings eliminates the underwater part of routine maintenance. 3. Carefully designed anti-off chain system.