Prefabricated balcony is divided into terraces (semi-prefabricated) and full prefabricated balconies. The flatness of the surface of the full prefabricated balcony can be as flat or concave as the surface of the mold, and the slope and outlet of the ground can also be prefabricated in the factory. Prefabricated balconies save on site moulding and high cost support. In the laminated board system, the prefabricated balcony, the superposed floor slabs, and the laminated wall board can be cast in one piece at a time.