Secondary cabin top cover diversion trench type waterproof structure

The invention discloses a secondary cabin top cover diversion trench type waterproof structure. The secondary cabin top cover diversion trench type waterproof structure comprises a diversion trench, wherein the diversion trench comprises a pipeline and a cross section, and the cross section is provided with a bottom edge, a web edge and a wing edge; the bottom edge and the web edge form an opening, and the bottom edge, the web edge and the wing edge form a shape like a Chinese character " ji "; the diversion trench is placed in an inverted mode, the opening faces upwards, and the pipeline of the diversion trench extends in the direction parallel to the bevel edge of a herringbone beam and is welded to the bevel edge of the herringbone beam; and top cover plates are welded to the wing edgeof the diversion trench after assembled and are folded downwards to form a lower step surface, and a plurality of long kidney-shaped holes are formed in the lower step surface. According to the secondary cabin top cover diver