House building drainage device

The utility model relates to the technical field of building drainage, in particular to a house building drainage device which comprises a gutter, the bottom end of the gutter is communicated and connected with a water collecting pipe, a protective shell is installed inside the gutter close to the water collecting pipe, and four corners of one end of the protective shell are fixedly connected with connecting rods. The protective shell is installed in the water guide groove, impurities such as fallen leaves accumulated on the roof can be prevented from directly entering the water collecting pipe, the filter screen frame is installed among the four connecting rods, a filter screen of the filter screen frame can filter the impurities such as the fallen leaves in rainwater, collection of the impurities such as the fallen leaves is achieved, the impurities are prevented from entering the water collecting pipe, and the rainwater collecting effect is improved. The outer water collecting tank is connected to the bott