An intergranular insulated Fe/SiO2 soft magnetic composite has been designed to reduce the core loss and improve the magnetic properties of cores by a modified Stober method combined with the spark plasma sintering. Most of conductive Fe particles could be coated by insulated SiO2 using the modified Stober method. In the spark plasma sintering, the high compact and intergranular insulated cores were obtained quickly. The Fe/SiO2 composite core displayed much higher electrical resistivity, lower core loss, better frequency stability of permeability and higher quality factor than that of the raw Fe core without insulated SiO2 layers. The model introduced here provides a promising method to reduce the core loss and improve the magnetic properties for soft magnetic composite materials, which can reach larger energy conversion efficiency for electric-magnetic switching device. (C) 2016 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.