In the present study, AC7A aluminum alloy casting mold which consist of 8 pieces is introduced as an analysis model. Also, numerical work using a finite element method was applied to investigate the thermal strain that included the temperature distribution, stress and strain during the cooling process in AC7A casting mold. In addition, the numerical work was carried out that analysis results of the AC7A casting mold were compared with those of mild steel casting mold to prove the improvement and good quality. The numerical results such as temperature distributions, stress and strain are presented to help to make the effective and the best tire mold. In addition, the introduced technique of numerical work using a finite element method is very useful and especially needs to improve the precision of tire mold such as sectional type or puzzle type.