In this article, the epoxy-based shape memory polymers were exposed to simulated -radiation environments up to 140 days for an accelerated irradiation. The influence of -radiation on thermal and mechanical properties was evaluated by differential scanning calorimetry, dynamic mechanical analysis, and tensile test. The glass transition temperatures (T_g) determined by differential scanning calorimetry and dynamic mechanical analysis decreased no more than 10%, and the shape recovery speed became a little faster after -radiation of 1 x 10⁵ Gy. The tensile strength and elastic modulus could, respectively, maintain 26 MPa and 1.36 GPa after being irradiated by 1 x 10⁶ Gy radiation, showing great potential in aerospace structural materials.