Abstract: Although graphene-based composites have been considered desirable candidates for thermal management applications, their poor electrical insulation restricts their further use in electrical insulation requiring occasions. Fluorinated graphene (FG), a new type of graphene-based material, attracts the attention of researchers due to its excellent electric insulation property. In this work, a novel fluorinated graphene aerogel/polydimethylsiloxane (FGA/PDMS) composite with a tightly-packed structure is constructed via freeze-drying and vacuum impregnation. The fabricated composite shows high compressibility and superior thermal conductivity of 1.41 W/(m⋅K) with a relatively low FGA loading of 0.28 wt%, 605.6% larger than the original PDMS. Meanwhile, it also maintains excellent insulation properties with an ultra-low electrical conductivity of 2.0 × 10− 9 S/cm. 180 times smaller than graphene aerogel/PDMS. The practical excellent heat dissipation performance of the composite functioning as thermal interface material is also verified by a thorough study theoretically and experimentally. Furthermore, the FGA/PDMS composite also behaves with excellent flame retardant properties.