Abstract The polymer-based magnetoelectric composites were prepared by the tape-casting method. The poly(vinylidene fluoride)-BaTiO3/poly(vinylidene fluoride)-Sr2CoMoO6/poly(vinylidene fluoride)-BaTiO3(abbreviated as PVDF-BTO/PVDF-SCMO/PVDF-BTO) sandwich structured composites possess strong non-volatile voltage control of magnetization and magnetodielectric properties. It is interesting that the magnetization of the sandwich-structured composite film significantly changes by different poling field, which is possibly originated from the electron orbital reconstruction of Co induced by the interface bound charges. Meanwhile, the response of the dielectric performance under the applied magnetic field is also obvious, which exhibits a maximum negative magnetodielectric coefficient of 10.2%. Our results may provide a new way in the design of polymer-based multiferroic materials and show potential application for multiferroic materials.