In this study, five types of compressive strength were derived from a 600 × 600 × 700(mm) column specimen, and FEM analysis was conducted to examine the differences in temperature stress and thermal crack ratio according to the method of compressive strength input. In the 600 × 600 × 700(mm) model, the temperature stress of the central compressive strength input model was 78.5% higher than that of the mixing strength input model, leading to differences in the thermal crack ratio. The thermal crack ratio of the mixing strength input model was 59.6% higher than that of the standard curing specimen input model, while the thermal crack rat io of the outer section, average, and central compressive strength input models was 26–60% lower than that of the mixing strength input model. Even for models of the same size, differences in temperature stress and thermal crack ratio were observed depending on the compressive strength input method, indicating the potential for overestimation in the analysis. To prevent such discrepancies, it is necessary to establish clear criteria for the input of compressive strength data.