In the present work, high-frequency induction heating is used to fabricate TiB 2 SiC ceramics and the relative density was more than 97%, and then the thermophysical properties of TiB 2 SiC ceramics were investigated in detail. The specific heat showed the weak dependence on the test temperature due to the presence of the interface gap because the relative density was not 100%. As the sintering temperature increased, the thermal diffusivity of TiB 2 SiC ceramics increased, which was due to the increase of relative density and grain growth. The thermal conductivity of TiB 2 SiC ceramics showed a marked increase with increasing grain size and relative density. This could be attributed to a reduction in the number of grain boundaries that interrupt the heat flow path, resulting in an increase in the mean free path of the phonons. Larger grains led to an increase of mean free path of the phonons and thus contributed to a further increase in thermal conductivity.