0.6［(1-x)(Bi0.5Na0.5)TiO3-xNaSbO3］-0.4(Sr0.7Bi0.2)TiO3 ceramics (abbreviated as BNT-NSO-SBT-x) was prepared by the conventional solid state reaction method, where x=0.04 mol, 0.06 mol, 0.08 mol and 0.1 mol. The effects of the third component NaSbO3 on the phase structure, dielectric and ferroelectric properties, and energy storage properties of BNT-NSO-SBT-x ceramics were studied. Sb5+ has no significant effect on the phase structure, and BNT-NSO-SBT-x ceramics have a coexistence phase structure of rhombohedral and tetragonal at room temperature. BNT-NSO-SBT-x ceramics are relaxor ferroelectrics with typical dispersion characteristics (γ~ 2). This is due to the inhomogeneous composition caused by complex cation occupation in A and B-site, and the inhomogeneous structure caused by the coexistence of rhombohedral and tetragonal PNRS. When the substitution amount of Sb5+ increases, Tp and Tm gradually approach. Because the Tp (<80 ℃) closes to room temperature, the weak polar tetragonal PNRs enhance. It deteriorates the ferroelectric performance of the ceramic, but it’s beneficial to improve the energy storage characteristics. The energy storage of BNT-NSO-SBT-x ceramics with x=0.06 is better, W1=0.227 J/cm3, η=76.2% (E=40 kV/cm, f=10 Hz).