Abstract: Fe3O4@SiO2@IPDI-HEA nanoparticle was prepared by solvothermal method with Fe3O4 nanoparticle as the core and acrylate as the shell. The structure of the nanoparticle was characterized by IR, TEM and XRD. The effect of the nanoparticle on the performances of water-borne polysiloxane-polyurethane photocuring system were studied by photo-DSC and TGA. The results show that the addition of Fe3O4@SiO2@IPDI-HEA particle did not obviously influence the photopolymerization property of the system, but improved significantly the heat resistance and tensile strength of the cured film. When the mass fraction of Fe3O4@SiO2@IPDI-HEA was 1.5%, the initial decomposition temperature (T5%) of the cured film was increased by 21.9 ℃, and the tensile strength was enhanced by 6.9 MPa. Moreover, Fe3O4@SiO2@IPDI-HEA can impart certain electromagnetic properties to the UV-cured film. When the frequency is in the range of 0 to 107 Hz, the dielectric constant is above 4.