▎ 摘　　要

NOVELTY - Selective composite film, is claimed. The composite film is formed by crushing, mixing and hot-pressing a barium titanate/polyvinylidene fluoride composite material and a grapheme/polystyrene composite material, where the graphene/polystyrene- barium titanate/polyvinylidene fluoride selective composite film is quaternary composite film with micro-capacitor structure. The barium titanate/polyvinylidene fluoride composite material is mixed by barium titanate (BT) and polyvinylidene fluoride (PVDF) and graphene/polystyrene composite material is formed by mixing graphene (GNP)and polystyrene (PS). USE - Used as selective composite film. ADVANTAGE - The composite film: has micro-capacitor structure, high breakdown field strength and excellent comprehensive performance; and improves the dielectric constant. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing a GNP/PS-BT/PVDF selective composite film comprising (i) mixing PS and GNP to obtain a GNP/PS composite material, (ii) mixing PVDF and BT to obtain a BT/PVDF composite material, (iii) crushing the GNP/PS composite material and BT/PVDF composite material, mixing the crushed two composite materials and then mixing to obtain a GNP/PS-BT/PVDF blended material, and (iv) preheating the GNP/PS-BT/PVDF blended material, then carrying out hot pressing and cooling.