The utility model discloses a solid-liquid separation device for dredging slurry in a channel. The solid-liquid separation device comprises a slurry storing container, a filter press, an earthwork transmission device and an earthwork storing container, which are sequentially mounted, wherein the filter press comprises an outer cylinder, an inner cylinder and a baseplate; the outer cylinder is in a cylindrical structure and connected with a clean water inlet pipe and a waste water discharge pipe; the inner cylinder is in a cylindrical structure of which the bottom is as high as the outer cylinder, the inner cylinder is placed in the outer cylinder, and a filtration hole is formed in the wall of the inner cylinder and connected with the slurry storing container through a slurry inlet pipe penetrating through the outer cylinder; the baseplate is connected with the bottom of the outer cylinder; a gravity bar is arranged above the filter press; one end of the earthwork transmission device is arranged below the discharging end of the filter press, and the other end of the earthwork transmission device is arranged above the earthwork storing container. The solid-liquid separation device has the functions of solid-liquid separation and slurry solidification.