(1-x)NBT-xBY(x = 0.00-0.04) ferroelectric ceramics were fabricated by a solid-state reaction method, and the crystal structure, surface morphology, dielectric, ferroelectric and energy storage properties of NBT ceramics incorporated BY were investigated in detail. Introduction of BY can transformed the phase of NBT from rhombohedral phase R3c to pseudo-cubic phase Pm3m, and make the diffraction peak shift to a lower angle with increasing BY content. Incorporating BY into NBT matrix contributes to the grain refinement for NBT ceramic, and enhances the relaxation performance to a certain extent. The largest dispersion coefficient is obtained when BY content is 0.02. In addition, the dielectric constant decreases with incorporating BY. The introduction of BY into NBT can greatly increase Eb, triangle P, Wrec, and eta, as well as a small decrease in Pmax. When x = 0.010, the relative best energy storage performance is obtained, Wrec = 2.07 J/cm3, eta = 31.66%, which is 10 times and 8 times higher than that of pure NBT ceramics, respectively. This work provides a strategy to strengthen the relaxation behavior and enhance the energy storage performance of ferroelectrics. These findings suggest that the instruction of BY into NBT is an effective method to improve the energy storage properties of NBT ceramic.