In this paper, a method of representing 3D shape for the laser-plasma scanning 3D display devices using point cloud in consideration of hardware is proposed. A new device has been developed for 3D spatial displays. This device generates plasma luminous bodies produced by "laser-induced breakdown" in midair. In this method, objects are represented by point cloud so that the burden of the xyz-scanner, which controls the position of the plasma, becomes lighter. Additionally, the order of drawing 3D wireframe models can be decided in consideration of the scanner burden.