Abstract: The embedded capacitor with good flexibility is a key component of the flexible printed circuit board, which has a broad application prospect in the field of national economy and defense industry. In order to obtain a kind of flexible capacitor material with high dielectric constant, with functionalized nano barium titanate (BT) particles as the filling agent and PVDF as the flexible matrix, the three-layer composite film with a sandwich structure (PVDF/BT//PVDF//PVDF/BT) was prepared by solution casting method and multilayer hot pressing method. The phase structure, micro morphology and dielectric properties of the prepared film were discussed. The results show that the structure of the films obtained by hot pressing is compact without obvious defects. With the increase of BT content, the dielectric constant of the films increases. As the ratio of PVDF:BT was increased to 1:6, the dielectric constant is 38.9, which is 412% higher than that of pure PVDF, and the three-layer composite film still has good flexibility. The comprehensive experimental research content of the PVDF/BT nanocomposite film involves material composition, structure, design, preparation and performance. Through the comprehensive experiment, students can further understand the main content of research in the field of materials science, which plays a positive role in promoting the formation of students’ innovative thinking.