Using SiO2 as carrier and decanoic acid-palmitic acid as phase change material, decanoic acid-palmitic acid/SiO2 composite phase change material was prepared by sol-gel method, its thermal storage and thermal conductivity performances, microstructure and composition structure were characterized. The results show that when the amount of decanoic acid-palmitic acid is 0.08 mol, the preapred material haa the best thermal storage performance, such as phase change temperature is 20.02~22.08℃ and phase transition enthalpy 44.53~50.51 J/g, being suitable for application in the field of architecture. When the amount of decanoic acid-palmitic acid is 0.06 mol, the material has the best thermal conductivity performance, such as its thermal conductivity in the first stage of cooling is 0.211 W/(m×K), 0.017 W/(m×K) in the stage of phase plateau and 0.040 W/(m×K) in the second stage of cooling. SiO2 in the material is physically embedded with decanoic acid-palmitic acid, there is no chemical reaction between them. When the content of decanoic acid-palmitic acid is excessive, by which SiO2 is covered, the thermal storage and thermal conductivity performances are decreased.