Skylight rear drainage sheet

A V-shaped water wall is arranged above a bottom plate, a water outlet pipe is arranged on the water wall, and a glue injection groove is formed in the position, in front of the water wall, of the bottom plate. The water wall comprises an inner water wall and an outer water wall which form an included angle, an inner wallboard is arranged at the front end of the inner water wall, an outer wallboard is arranged at the front end of the outer water wall, and the inner wallboard is parallel to the outer wallboard; a sealing plate with a glue groove is arranged at the front end of the outer wall plate, and a flow guide slope with a glue groove is arranged at the front end of the inner wall plate. A bolt hole and a buckling groove are formed in the bottom plate on the outer side of the sealing plate; bolt holes are formed in the bottom plate on the outer sides of the diversion slopes; the glue injection groove is communicated with the diversion slope and the glue groove of the sealing plate;a flow guide column is a