Abstract: This article takes large volume poured concrete structures as the research object, uses Analysis software to establish a thermal mechanical coupling model, and simulates the temperature field distribution characteristics and structural crack evolution law of concrete poured structures at specific construction times under four different concrete injection temperatures. The results show that there is a positive correlation between the injection temperature and the temperature rise of the structure. Lowering the injection temperature of concrete can effectively reduce the peak structural temperature of the structure and narrow the temperature difference between the structures; As the molding temperature decreases, the temperature transition zone between the boundary of the concrete surface and the interior becomes less obvious, which is caused by the combined effect of heat exchange efficiency and boundary effects; The concrete at the central depth exhibits the highest structural temperature, which will facilitate the accumulation of tensile stress in the concrete structure; The number and length of structural cracks also reflect a positive correlation with the molding temperature. As the molding temperature decreases, the length of structural cracks exhibits a significant exponential decrease; As the temperature of concrete entering the mold decreases, the number of surface large cracks will continue to decrease, and in space, it will gradually shift from a distribution pattern of intersecting large cracks to a distribution pattern of uniformly dispersed small cracks.