Abstract The development of pulsed power technology demands high energy storage density dielectric materials. In this study, Sr 0.7 Bi 0.2 TiO 3 relaxor ferroelectric (rFE) ceramic thick films were prepared using a tape-casting process. The ceramics exhibit a dense structure and typical rFE hysteresis curves, achieving an energy storage density of 4.77 J cm −3 and efficiency of 94.4%, attributed to the high polarization intensity, low remnant polarization, and low hysteresis loss of rFE. Additionally, the material demonstrates good temperature stability. Moreover, the Sr 0.7 Bi 0.2 TiO 3 ceramic thick films show advantages in charge-discharge performance, capable of discharging within hundreds of nanoseconds and achieving a power density of 137 MW cm −3 . Overall, the Sr 0.7 Bi 0.2 TiO 3 ceramic thick film exhibits a comprehensive performance advantage in terms of energy storage density, efficiency, and power density. Additionally, the material was fabricated using the tape-casting process, which is compatible with subsequent multilayer ceramic capacitor production, indicating potential for further performance enhancement.