The high chain grille is mainly composed of a driving device, a frame, a cleaning rake, and a slag unloading mechanism. The triangular pole frame node on the cleaning rake is hinged with the chain, and the roller on the other node is located in the channel steel guide rail parallel to the grid bar. The toothed rake is fixed on the bottom edge of the triangular pole frame. When the chain is driven by the top driving device (the sprocket rotates clockwise), the toothed rake frame is constrained by the chain bar and guide rail to move in a plane. Within one week of the chain running, it completes the cyclic actions of the toothed rake closing underwater slag collection, upward slag transportation, and rake rotation. During this process, when the toothed rake moves upward and touches the top slag discharge plate, under the relative motion of the two, the slag is skimmed out and discharged into the slag bucket or conveyor through the slag guide plate.