Abstract: Geostationary satellite may be subjected to the charged particle radiation on-orbit, with the total ionizing dose to cause a significant damage to the onboard electronics. During the structural design for the satellite, some materials such as the tantalum foil are used to plug up holes on the honeycomb sandwich board. The shielding effectiveness for the satellite is determined through a three-dimension analysis of the radiation dose. The shielding depth model of the satellite in three dimensions is established to compare the total ionizing dose before and after the shielding design, and the influence on the mechanical and thermal system of the satellite is analyzed. The result have validated the effectiveness of the proposed approach is validated.