Dewatering device for deep and large foundation pit

The utility model relates to foundation pit drainage equipment, in particular to a deep and large foundation pit dewatering device which comprises a water collecting main pipe, a well point pipe and a water suction pump, the water collecting main pipe is a rectangular closed-loop pipeline, a water outlet and a plurality of water inlets are formed in the water collecting main pipe, the water outlet is connected with the water suction pump, and the well point pipe is connected with the water suction pump. The water inlet is connected with the well point pipe, the well point pipe comprises a bent connecting part and an infiltration part which are perpendicular to each other, the infiltration part is a long-strip-shaped pipe body, the infiltration part sequentially comprises a cast iron head, a stabilizing part, a filtering part and a thick iron wire protection net part in the axis direction of the infiltration part, a plurality of through holes are densely formed in the stabilizing part, and the filtering part i