The associated modeling method of complex foundry system was investigated under software environment of PRO/E and ANSYS. The 3D-structure of K4169 superalloy shell castings constructed by applying PRO/E was guided into ANSYS to reconstruct the whole foundry system. The variation of temperature field with solidifying time was calculated by ANSYS to check each key node in casting structures. According to the temperature changing curves of key nodes, the grain structural feature values were obtained by using consecutive nucleation model. Based on the 2D cellular automaton method, the evolution of grain structure in some sections of casting was visually simulated. The results of simulation are good accordance with the measured grain feature values.