Construction method for transverse confluence under basement dewatering pipeline bottom plate

The invention relates to a construction method for transverse confluence under a basement dewatering pipeline bottom plate. The construction method comprises the following steps that firstly, dewatering pipes and exhaust pipes are pre-buried on the ground of a basement; 2, the downcast tube well is cut off below the elevation of the cushion layer, and a sealing cover is arranged at the upper end of the tube well; thirdly, a cushion layer and a structural bottom plate are poured above the horizontally-embedded downcast pipe and the horizontally-embedded exhaust pipe; 4, arranging a water collecting well on the ground outside the basement exterior wall; 5, fixing the vacuum pump; the vertical downcast pipes connected into the different pipe wells are connected with the corresponding vacuum pumps; 6, a vacuum pump is started, and water in the tube well is pumped up through the downcast pipe and discharged into the water collecting well; seventhly, the vertical downcast pipe is disconnected from the vacuum pump,