The rotary mechanical fine screens is a fine screens that can be continuously and automatically removed. It is composed of many identical rake gear parts staggered and assembled into a set of closed rake gear chains. Driven by a motor and reducer, a continuous top-down cyclic movement is formed by a set of sheaves and chains to achieve The purpose of constantly removing the fine screens. When the rake tooth chain runs to the upper and back of the equipment, due to the guiding effect of the sprocket and the curved rail, the parallel rake tooth rows can be misaligned, so that the solid dirt falls into the slag trough by its own weight. The similar fine screens easily brings dirt into the channel behind the fine screens.