A novel design method based on a novel origami process that can create a solid structure swiftly and at a low cost is presented for rectangular waveguide-type microwave devices in this paper. A planar structure was fabricated by the lamination and laser cutting of polystyrene membranes and aluminum foils and was converted into a solid structure via origami in accordance with the selective absorption of infrared light. A rectangular waveguide, a rectangular waveguide-type coupler, and a power divider based on an origami structure with a multi-layer structure and a single-layer structure were fabricated and tested, demonstrating easy assembly and good microwave performance. The measured results of the rectangular waveguide indicated that the insertion loss was superior to -0.9 dB. Meanwhile, the results of the coupler showed that the coupling degree increased from -12.8 dB to -8.9 dB in the range of 11.0 GHz to 12.0 GHz. Correspondingly, the prepared power divider demonstrated that the return loss dwindled from -8.9 dB to -11.3 dB and that the insertion loss of one output port was approximate to that of the remaining one, varying between -3.5 dB and -5.2 dB in the range of 10.5 GHz to 11.5 GHz-verifying the effectiveness of the origami-based design method.