(1 − x)K_0.48Na_0.52Nb_0.95Sb_0.05O₃–xBi_0.5Na_0.5Zr_0.95Ce_0.05O₃ [(1 − x)KNNS–xBNZC] lead-free piezoelectric ceramics, with doping ratio of x ranging from 0 to 0.05, were synthesized by the conventional solid state sintering method. The phase transition behavior, microstructure and piezoelectric properties of (1 − x)KNNS–xBNZC ceramics were systematically investigated using XRD, SEM, and other devices with different doping amounts of BNZC. It was found that the piezoelectric properties of (1 − x)KNNS–xBNZC ceramics were improved obviously by adding the proper doping amount, 0.03 < x < 0.04, due to the coexistence of rhombohedral and tetragonal phases in the ceramics near room temperature. The piezoelectric constant d₃₃ of the ceramics first increased and then decreased when increasing the doping amount. A remarkably strong piezoelectricity was obtained in ceramics with a ∼441 pC N⁻¹ peak d₃₃ value. The excellent piezoelectric properties of (1 − x)KNNS–xBNZC ceramics with x = 0.034 were obtained: d₃₃ = 441 pC N⁻¹, k_p = 0.44, Q_m = 31, ε_r = 2447, tan δ = 0.037, T_C = 215 °C, P_r = 15.7 μC cm⁻² and E_C = 8.2 kV cm⁻¹. With the annealing temperature reaching 250 °C, the d₃₃ values of the ceramics were still greater than 330 pC N⁻¹, which represents good temperature stability for the piezoelectric property. It is believed that such a material system is a very promising candidate for lead-free piezoelectric ceramics.