The spiral case of Three Gorges Power Station's unit is characterized by high water head and big diameter, besides the exterior concrete layer of spiral case is relatively thin and loading conditions of spiral case are complicated. Whether the unit can work safely and stably depends on the burying scheme to obtain success. Employing the simulation model experiment technology can simulate the directly burying scheme of the No.15 unit's scroll case on the right-bank power station. The model is made of reinforced concrete with a scale 1∶72. The experiment researches mainly include stress, strain, the crack's degree of the structure and the influence of the repeatable loads on structure stress. According to the over-loading experiment, the rule of crack stretching out and the bearing capacity of structure are also studied. The research results show that this directly burying scheme is feasible, and the structure stable.