To address the issue that conventional polyimide dielectrics show sharp conduction loss increase and significant energy storage density/efficiency decline under high-temperature and high-electric-field conditions, this work designed and synthesized a series of imidazole-structured, wide-bandgap fluorinated copolyimides ( FPIPABZ) using 4,4′-( hexafluoroisopropylidene) diphthalic anhydride (6FDA) and 2,2′-bis( trifluoromethyl)-4,4′-diaminobiphenyl (TFMB) as matrix monomers with 2-( 4-aminophenyl)-5-aminobenzimidazole ( PABZ) as comonomer. The effects of PABZ content on the microstructure and high-temperature energy storage performance were systematically investigated. The results show that the introduction of PABZ creats hole traps within the FPIPABZ, which effectively captures carriers, thereby suppressing conduction current and improving energy storage efficiency. Additionally, the hydrogen bonds in PABZ strengthen intermolecular interactions and increas the elastic modulus of the FPI-PABZ, thereby enhancing breakdown strength and boosting energy storage density. When the PABZ content is 6% , the FPI-6% PABZ exhibits the highest breakdown strength of 563 MV/m at 150 ℃. Under the conditions of 150 ℃ and 550 MV/m, the energy density (U_e) reaches 3.91 J/cm³, with an energy storage efficiency (η) of 91.5% , demonstrating excellent high-temperature fatigue resistance. This study provides new insights and technical support for the design and fabrication of intrinsic polyimide dielectrics with high-temperature resistance, high energy storage density, and low loss.