Today, in the casting engineering field, various heat flow simulations are being applied to manufacturing processes. The most general flow simulation techniques have been improved and developed according to the characteristics where they are applied in the casting industry. In this study, the authors have developed a pre-/post-processing system to use a cut cell method, which is one of the finite volume methods among the numerical analysis methods mentioned above. In this paper, the authors will briefly introduce a pre-processor that requires only the user's simple input information to automatically generate meshes and performs simulation and post-processing, which maps the simulation result data into an original computer aided design file directly. This paper will also examine a few cases of actual application of these technologies to casting products.