Disclosed are a porous aluminum macroscopic body, a fabrication system, and a method therefor, where the porous aluminum macroscopic body is a three-dimensional full-through-hole structure formed by connecting hollow aluminum wires, and the wall thickness of the hollow aluminum wires is 7-100 micrometers. The fabrication system comprises a magnetron sputtering subsystem, a high-temperature aluminum vapor subsystem, a low-temperature aluminum deposition subsystem, an aluminum vapor recovery subsystem, and a porous polymer film conveying subsystem. A preparation method therefor comprises first utilizing a magnetron sputtering method to rapidly sputter on a porous polymer film to form an aluminum layer that has a thickness of 1-500 nm, and then continuing to deposit the aluminum layer to a thickness of 7-100 micrometers while decomposing the polymer film in-situ so as to obtain the porous aluminum macroscopic body.