Abstract: The poor damping performance of polydimethylsiloxane (PDMS), arising from its low interchain friction and regular molecular structure, motivates the need to improve its energy dissipation performance. Herein, hyperbranched siloxane clusters (TC) were first synthesized and subsequently used with hydroxyl-terminated polydimethylsiloxane (OH-PDMS) to prepare polyborosiloxane (PBS), which was further blended with PDMS to yield a dual-network, impact-resistant, high-damping silicone rubber. The effects of different TC addition amounts and different PDMS/PBS network ratios on the mechanical properties, rheological properties, and energy dissipation performance of the silicone rubber were systematically investigated. When the TC addition amount was 2 wt% of OH-PDMS and the PDMS/PBS ratio was 3:7 (mass ratio), the silicone rubber exhibited the best overall performance, achieving a modulus increase of up to 10 times under frequency variation, an elongation at break of 210%, and a loss factor higher than 0.3. Moreover, its damping performance remained stable over a wide temperature range of 25–125 ℃ under low-frequency conditions, opening a new avenue for the design of highly impact-resistant, high-damping elastomers with a broad temperature window.