Abstract: The sub-critical module-fuel component is the core component of the sub-critical blanket in fusion–fission hybrid energy system. The thermal safety experiment for module-fuel component is the foundation and necessary step of obtaining thermal design principle, developing structure design and safety analysis. In this paper, the necessary experiment modeling technique of thermal safety experiment is researched. The analysis for the particular thermal-hydraulics structure is developed. The related calculation, by computational fluid dynamic（CFD） method, is developed to confirm the parameter of object. The structure abstraction of typical thermal experiment unit is obtained. This work supplies the basis of following experiment body design.