A two-dimensional transient global model was developed for the industrial directional solidification furnace. Two models of elastic coefficients of crystalline silicon ingot were employed to investigate their influence on the thermal stress distributions in the silicon ingot in the solidification,annealing and cooling processes,respectively. The research demonstrates that the thermal stress distributions in the silicon ingot vary significantly at different stages. The thermal stress distribution patterns in the silicon ingot obtained with the two models of elastic coefficient are similar. However, the magnitudes of thermal stress in the solidification and cooling processes are quite different from each other with different models.