Abstract: Terahertz(THz) imaging technology provides perspective applications in non-destructive inspection, medical diagnostic and national defense. An integrated terahertz confocal imaging system based on THz waveguides was reported in this paper. Firstly, a reflective THz imaging of a metal razor blade with lateral resolution close to wavelength (3 mm) was acquired. Then, a reinforcing metallic bar in concrete was detected effectively, which provided a feasible method to ensure the quality of construction. Further, by introducing a pinhole before the THz detector, a THz confocal imaging system was set up and depth information(24 mm) between two nails inserted in different depths in insulating foam could be extracted, which was three-dimensional information. The results show that the proposed terahertz confocal imaging system based on waveguides structure has the advantages of compact structure and portable integration, which is especially suitable for practical engineering applications.