The CrZrCu alloy cylindrical ingots have been tried to produce by the direct chill (DC) casting process. However crack defect is contained in the central area of the ingots. Metallographic analysis proving a kind of hot crack is cause by the precipitate in grain boundaries. A 3D coupled thermal-stress mathematical model has been formulated to describe thermal and stress–strain fields during the direct chill (DC) casting process for CrZrCu alloy cylindrical ingots. The model has been applied to analyzing the crack defect elimination, so that the need for further refinement of the DC casting process parameters has been satisfied.