Abstract: A soft-template-directed assemblyand calcination strategy was innovatively developed to synthesize silica hollow raspberry-like microspheres (HRP) with refined architectures and pioneered the construction of an HRP/epoxy resin (E51) low-dielectric composite system. Utilizing a Pickering emulsion polymerization approach, hybrid hollow microspheres (HHRP) were fabricated by precisely regulating oil/water interfacial stability through surface modification of SiO₂ nanoparticles with 3-(methacryloyloxy)propyltrimethoxysilane (TPM), followed by calcination at 600℃ to achieve HRP structures with a shell thickness of 25 nm and a uniform particle size of 360 nm, ensuring complete removal of soft templates and organic residues. An in-situ curing and blending process enabled the integration of HRP (5~10wt%) into E51, systematically elucidating the structure-property relationships. HRP retained intact hollow structures during curing, forming a dense Si-O-Si network that effectively blocked resin infiltration, establishing a unique core-shell reinforcement mechanism. Fracture surface analysis revealed HRP induced high-density plastic cavities, significantly enhancing fracture toughness via toughening mechanisms of stress dissipation by crack tip blunting. Dielectric testing indicated the 10% HRP/E51 composite exhibited an average dielectric constant of 4.11 (10¹~10⁶ Hz), representing a 23.2% reduction compared to E51 (5.35), with excellent agreement to the Lichtenecker model. Thermal analysis confirmed HRP incorporation increased the initial decomposition temperature (T_5%) by 14℃ to 386℃, the peak mass loss temperature (T_max) by 10℃ to 430℃, and the glass transition temperature (T_g) from 72℃ to 84℃, achieving comprehensive thermal optimization. This work breakthroughs in synergistically enhancing dielectric and thermal properties, offering novel strategies for high-frequency electronic packaging materials and advanced thermal management systems, with significant potential in 5G communications and high-density integrated circuits.