A new type of silicone rubber (SR)-based gamma radiation shielding and thermal regulation composite was developed with paraffin (Pn) @lead tungstate (PWO) phase-change microcapsules as functional fillers. These SR/Pn@PWO composites have a PWO component that not only exhibits excellent photon attenuation but also can provide a barrier to the molten phase-change material core. The thermal and mechanical properties of the composites were characterized by differential scanning calorimetry, thermal regulation experiment and mechanical tests. Thermal analysis indicated that the SR/Pn@PWO composites not only reveal reliable energy storage performance which can reach to 52.72 J g(-1) enthalpy values but also exhibit good thermal durability. In addition, SR/Pn@PWO composites have enhanced mechanical properties and excellent thermoregulation performance. And the more microcapsules content, the more significant enhancement effect is. A high-purity germanium gamma spectrometer to measure the attenuation coefficient of the composites for gamma radiation showed that the SR/Pn@PWO composites have good gamma-ray-shielding property, which increased with the increase of the microcapsules content.