This article uses NPGDMA as the monomer, and uses light curing technology to polymerize the monomer to form a polymer into a 3D network structure. This structure can effectively wrap the ODE to solve the leakage of octadecane. By using high thermal conductivity BN as a thermally conductive filler, an ODE/NPGDMA/BN composite PCM with good thermal conductivity and shape stability was successfully prepared. When the mass ratio of ODE and NPGDMA was 1:1, it had a lower leakage rate and a larger latent heat. Therefore, a formula with an ODE content of 50% was selected for subsequent experiments. The structure, morphology and element distribution state were characterized by FTIR, XRD, SEM and EDS. The hot stage test showed that the prepared composite PCM had no shape change when it is higher than the ODE phase transition temperature (28 ℃), indicating that it has good shape stability; through TGA test, it can be seen that there was no weight loss before 100 ℃, indicated that the composite PCM had good thermal stability; The DSC test showed that the ODE/NPGDMA/BN composite PCM had a large latent heat (103.9 J/g). When the content of BN in the composite PCM was 5%, its thermal conductivity was increased by about 49.6% compared with pure ODE.