To meet requirements of miniaturization devices in high pulsed power technology, super dielectric energy storage performance, such as high dielectric breakdown strength (DBS), large energy storage density with high power density, is extremely important in dielectric materials. However, for BaTiO3 based ceramics and glass ceramics, there is still a critical challenge to achieve high DBS and large energy storage density. Herein, a novel route was proposed to precipitate nanocrystals with cubic BaTiO3 phase from glass matrix, which can elevate dielectric constant and meanwhile maintain high DBS compared to parent glass. A high recoverable energy storage density of ∼ 3.66 J cm−3 at 1000 kV cm−1 and high discharge energy density of ∼3.57 J cm−3 with good thermal stability and ultra-high peak power density of ∼ 910 MW cm−3 can be achieved in BaTiO3 glass ceramic, which implies this type of glass ceramics is suitable for high pulsed power technology application.