In this paper, we propose a photonic terahertz (THz) continuous-wave computed tomography (CT) system employing an optical frequency comb and specialized imaging algorithms. Our work leverages the system to offer unique advantages in detecting and analyzing samples that are challenging for traditional 2D scanning systems. Our experimental results, operating at 330 GHz, reach an exceptionally low amplitude standard deviation of 0.016 mV. Additionally, the proposed system performs nondestructive CT detection with a 0.5 mm error margin and obtains enhanced image quality, showing its great promise for implementing THz-CT imaging with high robustness and resolution.