The invention provides a special building walling tool which comprises a columnar cylinder enclosed by a plate. The columnar cylinder comprises a slot bottom plate and a slot screen plate directly facing the slot bottom plate, a pair of foldable plates are symmetrically arranged on two sides of the slot bottom plate and the slot screen plate, the slot bottom plate and the slot screen plate are pivoted through the foldable plates, folded shafts of the foldable plates and pivot shafts among the foldable plates, the slot bottom plate and the slot screen plate are spring shafts, the columnar cylinder is a rectangular cylinder when the spring shafts are in a natural state, and a baffle plate is arranged at the rear end of the columnar cylinder, is fixedly orthogonal with the slot bottom plate, covers a through hole in the rear end of the columnar cylinder when the spring shafts are in the natural state and is connected backwards with a handle. Walling efficiency can be effectively improved by the aid of the special tool.