An innovative design method inspired by origami is proposed for the 3D-shaped microstrip microwave device in this paper. A self-assembled microstrip low-pass filter inspired by the origami structure is designed, fabricated, and measured. The experimental results of the prepared prototype demonstrate the validity of the origami-based design method for stereoscopic microstrip microwave devices. This work provides a simple method to fabricate thin stereoscopic metal structures of microstrip microwave devices.