Thermal energy storage with phase change materials (PCM) is of great significance for increasing energy efficiency and energy saving. In this paper, a novel capric acid-myristyl alcohol/expanded perlite composite PCM (CPCM) with two phase change peaks were prepared. The capric acid-myristyl alcohol (CM) were synthesized by capric acid (CA) and myristyl alcohol (MA) (W-CA and W-MA = 9:1). Three kinds of expanded perlites (EP) were employed as support materials in the prepared CPCM. The chemical structure, morphology, thermal properties, leakage and thermal energy storage performance of the CM/EPPCM were investigated. The results indicate that the CM/EPPCM has a good thermal stability and leakage-proof performance. In addition, the thermal characteristics of the CM/EPPCM were investigated using a building model. The experimental results shows that the application of the CM/EPPCM for building envelope can effectively reduce temperature fluctuation and improve the thermal comfort of the building.