Many factors affect the strip thickness in the industrial production process of twin‐roll strip casting, such as pouring temperature, casting speed, cooling capacity, cast‐rolling force, and so on. When the pouring temperature and cooling capacity are specified, the magnitude of the cast‐rolling force is determined by the actual roll gap, which has a significant effect on the thickness, shape, and surface quality of the cast strip. As a result, the actual roll gap size is critical for smooth realization. In the actual casting process, thermal deformation is a direct factor influencing the change in roll gap shape for a given roll gap value. Hence, any factor influencing the thermal deformation indirectly influences the roll gap shape. Thus, the critical factors determining the thermal deformation are simulated and studied in this research, which is integrated with actual production, based on the application and secondary development of ANSYS. The effect law of each process parameter on the thermal deformation of the casting roll is given, and corresponding mathematical models are established. This research lays the foundation for the establishment of the cast strip thickness control model and the realization of online control of strip thickness.