In order to develop the application of energy storage ceramics, the dielectric properties and energy storage density of Ba0.1Sr0.9Zr0.18Ti0.82O3 ceramics (BSZT-118) prepared by the modified sol-gel process were researched under different temperatures under electric field. The results show that the dielectric constant of BSZT-118 is consistent with Johnson's formula based on Devonshire phenomenological theory, and the anharmonic constant (alpha) increases as the temperature rises. The energy storage density of BSZT-118 is influenced by the electric field and temperature. With the increase in temperature, the storage density of BSZT decreases and the fluctuation of storage density increases under electric field. The conduction mechanism of BSZT-118 is mainly space charge-limited conduction (SCLC) below 60 degrees C, and it is mainly Ohmic conduction above 60 degrees C.