Abstract: Polymers such as polyvinylidene fluoride (PVDF) are limited by their low thermal conductivity, and it is important to enhance the thermal conductivity of polymer-based composites by adding thermally conductive fillers. In this paper, Al₂O₃-BNNS/PVDF composites with enhanced thermal conductivity were prepared by hot-compaction process using hexagonal boron nitride nanosheets (BNNS) and spherical alumina (Al₂O₃) as thermally conductive fillers. Firstly, BNNS nanofillers with thickness of 3-5 nm and diameter of 1-5 μm were prepared by exfoliation in green solvents consisting of choline chloride (ChCl) and aqueous phytic acid (PA). Then, based on the synergistic effect of BNNS and Al₂O₃ hybrid fillers, the thermally conductive composites with a pea pod-like structure were fabricated by solution blending-hot pressing, and a good three-dimensional heat conduction network was constructed. When 30wt%Al₂O₃ and 20wt%BNNS were added, the in-plane thermal conductivity of the composite was as high as 11.54 W/(m·K) and the vertical thermal conductivity was 5.70 W/(m·K). The thermal conductivity of the composite was greatly improved, showing excellent thermal performance.