Prefabricated drainage device for fabricated roof

The prefabricated drainage device comprises a building body, a water collecting mechanism, a drainage pipe and a fixing device, the water collecting mechanism is arranged on the side face of the roof of the building body, the drainage pipe is arranged below the water collecting mechanism, and the fixing device is arranged on the drainage pipe. The drainage pipe is connected with the wall face of the building body through a fixing device. According to the prefabricated drainage device for the assembly type roof, fallen leaves or other sundries are isolated from the eave gutter through the cover plate, the fallen leaves or other sundries are prevented from falling into the eave gutter and entering the drainage pipe, water normally enters the eave gutter from the through hole, the problem that the fallen leaves or other sundries block the drainage pipe is solved, the drainage efficiency of the drainage pipe is guaranteed, and the service life of the drainage pipe is prolonged. The drainage pipe is divided into a