PURPOSE: A device for constructing the outer wall of a building capable of being constructed without field welding is provided to ensure safe and comfortable working environment, reduce construction period and costs and realize a relatively firm outer wall. CONSTITUTION: A device for constructing the outer wall of a building capable of being constructed without field welding comprises a plurality of horizontal beams(20,21), a plurality of vertical beams(40), and a plurality of plate structures(60). The horizontal beams are fixed horizontally along the outer surface of slabs(2,4) through at least one first elbow bracket(10). The vertical beams are fixed vertically along the outer surface of the horizontal beam through a band bracket(30). The plate structures are fixed vertically along the outer surface of the vertical beam to form an outer wall.