There are many researches about preparing conductive composites by the employment of expandable graphite (EG), yet thermally conductive and electrically insulative composites can be obtained by manipulating the amount of low temperature expandable graphite (LTEG) below its electrically conductive percolation threshold. The study aims at investigating the synergistic effect of the integration of two dimensional LTEG lamellae and zero dimensional α-Al2O3 particles on the thermal properties of polyamide 6 (PA6) based composites. LTEG possesses both a large aspect ratio and a fairly high intrinsic thermal conductivity, which is of great benefit to boost the thermal conductivity of composites effectively. In this work, high thermally conductive polyamide 6 composites with hybrid fillers were obtained via the in situ exfoliation of LTEG during melt blending. The hot-disk method was applied to measure the thermal conductivity and the results manifests that the thermal conductivity of the composites containing hybrid fillers (5 wt% of LTEG and 60 wt% of α-Al2O3) reached 2.019 w/(m·K), which is about 6.37 times that of the pure PA6 and 1.40 times that of the 65 wt% of α- Al2O3 filled composites respectively. Measurements of the volume resistivity (ρv) of composites were performed by the ZC-36 insulation resistance tester. The results illustrate that the incorporation of LTEG has a negative impact on the volume resistivity which decreases by 3 orders of magnitude from 10^16 of the pure PA6 to 10^13 of the 65 wt% of hybrid fillers (5 wt% of LTEG and 60 wt% of α-Al2O3) filled composites which can still be regarded as electrically insulative. The noticeable improvement of the thermal conductivity is ascribed to the synergistic effect of the lamellar LTEG and alumina particles, i.e. the introduction of LTEG is propitious for the formation of efficient and developed thermally-conductive pathways resulting in a higher thermal conductivity.