In this study a multiscale numerical simulation was presented for multiferroic composite materials consisting of ferroelectric (FE), ferromagnetic (FM) and polymer phases to design the microstructure and the material combination. An asymptotic homogenization theory was employed to estimate macroscopic homogenized material properties. We focused on a polycrystalline layered structure to multiferroic polymer composite by 3D printer. Barium titanate (BTO) and polypropylene (PP) were utilized for FE composite filament. On the other hand, Terfenol-D (TFD) and PP were selected for FM composite filament. And then, we simulated material properties of polymer composites that mixing with polypropylene and FE/FM phase. At first the influence of the volume fraction of FE phase on macroscopic homogenized material properties was investigated. The optimum volume fraction was found to maximize macroscopic magnetoelectric (ME) effect. We discussed how to determine the microstructure, the material combination and the volume fraction to get the maximum ME effect.