Slag removal device for open drainage passing pipe of foundation pit

The invention relates to the technical field of foundation pit drainage, in particular to a foundation pit open drainage passing pipe slag removal device which comprises a winch and a mud scraping assembly, the mud scraping assembly is arranged in a passing pipe, the winch is arranged outside the passing pipe, and meanwhile the mud scraping assembly is connected with the winch through a steel wire rope. A blocking piece is arranged on the steel wire rope and arranged on the side, facing outwards, of the mud scraping assembly. According to the slag removal device for the foundation pit open drainage passing pipe, the interior of the passing pipe can be dredged and cleaned through the positive and negative different placement modes of the mud scraping assembly, meanwhile, the fixed main framework and the movable main framework are movably connected, the size of the mud scraping assembly can be changed along with the size of the inner pipe diameter of the passing pipe, and the size of the mud scraping assembly i