Abstract: Aiming at the problem of designing or preparing an X-ray testing system, the method through modeling and simulation was proposed. The current status and new horizons in the algorithmic simulation of X-ray imaging were discussed. A typical industrial product and its cavity and inclusion defects were modeled as CAD models. The radiographic simulation methods for lack-of-material and impurity were presented, and the whole radiographic testing system was simulated. High-quality radiographs were generated, which could be used as parameter adjastment and evaluation for NDT system. This work could be widely used in the process of research and development of NDT setups in industry and medicine as well as its operation efficiency improvement.