Objectives：In the Permian period, the Panthalassa encircled and subducted the Pangaea. In this context, the ocean basin within the Pangaea appears to be rotating and closing like a scissors, with the fluctuation of each other. Previous studies have explained the genesis of rift basins and the simple stress states of the interior of Pangaea by using the self-subduction plane model, but this model is quite different from the actual geological background. By means of numerical simulation, a more accurate mechanical model conforming to the geological background at that time will be established in this paper to analyze and discuss the mechanical state in the process of the Permian Pangaea pyrolysis. Methods：In this paper, a mechanical model of Pangaea in the Permian period was established by using a 3D spherical shell model and considering the effects of low-velocity zone of the African nuclear mantle boundary and the Arabian mantle plume on Pangaea, and the effects of subduction and closure of the Paleo-Tethys Ocean basin on the internal stress and strain of the continent after the formation of Pangaea were simulated. Results：The simulation results of Pangaea 3D spherical shell model 1 show that the axial tensile stress is mainly concentrated in the core of Pangaea, and there is also tensile stress in the south of the passive continental margin corresponding to the Hercynian orogenic belt and the southern side of the Paleo-Tethys Ocean. The axial compressive stress distribution is concentric and increased successively from the outside to the inside. The absolute value of the differential stress is larger in the central Eurasia and the Neo-Tethys Ocean. The simulation results of the pan-continental 3D spherical shell model 2 show that the tensile stress is mainly distributed behind the passive continental margin of the Paleo-Tethys Ocean, and the absolute value of differential stress is the largest in this region, which is prone to tectonic fracture. The strain vector diagram of the model shows that the maximum tensile stress occurs after the passive continental margin of the Paleo-Tethys Ocean, and the rupture is prone to occur parallel to the passive continental margin. Conclusions：The simulation results show that the 3D spherical shell model can well explain the large faults and residual ocean basins developed in the central Asian region during this period, and also support the geological phenomena of the clipping closure of the Paleo-Tethys Ocean basin and the opening of the Neo-Tethys Ocean basin from the back of the passive continental margin of the Paleo-Tethys Ocean basin. The mantle vertical action of the Afro-Arabian plate provides mechanical support for the opening of the Neo-Tethys Ocean basin. Because the old and new ocean basins were not limited to the old and new ocean basins in the process of the Pangaea splitting, the simulation results can be extended to other ocean basins.