Terahertz interferometric imaging technique based on the spectral domain, by sampling information of the spectral domain of the target scene to reconstruct the target image. It offers considerable potential in image acquisition rate and resolution for avoidance of scanning each pixel and ability to image with only a handful of detector elements. The terahertz interferometric imaging principle and implementation method were researched, then imaging resolution and effective field of view were focused on. Simulation experiments were carried out to analyze the influence of noise in target scene for imaging quality, and the results show that interferometric imaging is sensitive to noise. The reflection imaging model in security check was focused on which validated the applicability of the principle system. The conclusions from the simulation results may offer some theoretic evidence and technical support to designs of terahertz interferometric imaging system and practical applications.