The work aims to develop a phase change energy storage module and study its temperature control performance, in order to control the operating temperature of electronic equipment. The energy storage module with No. 32 paraffin, No. 62 paraffin and 6% expanded graphite (EG) - No. 62 paraffin wax as the phase change working medium was studied by simulation, and the effect of phase change materials, fin materials and heating power on the temperature control performance of the phase change energy storage module was analyzed. No. 32 paraffin nearly melted at 900 s, No. 62 paraffin only melted half of the way at 2 000 s, and the expanded graphite-paraffin composite material nearly melted at 1 250 s. The temperature rise rate of Al fin module filled with No. 62 paraffin was 0.035 ℃/s, and that of Cu fin module was 0.03 ℃/s. Compared with unfilled PCM modules, the temperature rise rate was reduced by 73.1% and 70%, respectively. Phase change materials with different physical parameters have different temperature control performance under different working conditions, but at higher power, the phase change materials with lower melting point or higher thermal conductivity have better temperature control performance. The internal thermal conductivity framework of the energy storage module has obvious effect on internal enhanced heat transfer, and the higher the thermal conductivity of the framework, the more beneficial the temperature control of the module.