Abstract: The composite phase change material (PCM) is a new type of phase change material with the high porosity foam as a thermal conductivity enhancer. It has lots of excellent performances including large amount of latent heat and higher thermal conductivity than pure PCM, which make the device with composite PCM for heat storage to be an efficient thermal management technique for the next generation aircraft. The thermal characteristics of SiC foam filled paraffin waxes were studied in this paper. To simulate the heat transfer of composite PCM, a finite volume technique was used to discretize the heat diffusion equation, and the two-temperature model was employed for the small scale material while the equivalent specific heat method was used for the large scale material. The experimental setup was build up and heat transfer experiments were performed to validate the proposed numerical method. The experimental and numerical results show good agreement, which indicates the effectiveness of the proposed numerical model in this work. Based on the numerical method, the effects of the porosity on the equivalent thermal conductivity, and the effects of the microstructure on the equivalent thermal conductivity could be studied in further work.