0.95(Na0.96−xKxLi0.04)(Nb0.89Sb0.07Ta0.04)O3-0.05KNbO3 (abbreviated as KxNLNST-KN, x = 0.32 − 0.52) lead-free piezoelectric ceramics were prepared by using the conventional solid-state sintering method, and the intentional addition of a pre-calcined KNbO3 powder was used as a sintering aid that might inhibit and compensate for the volatilization of alkali metals during the sintering process. The preparation of the ceramics and the effects of K/Na ratio on the structure and the electrical properties of these ceramics were studied in detail. Compared with the relatively higher sintering temperature of Li-, Sb-, and Ta-modified KNN ceramics reported in the literature, the dense ceramic samples were obtained at a reduced temperature of 1060 • C, and the ceramics with x = 0.44 possessed optimal properties: d33 = 298 pC/N, kp = 48%, Pr = 21.9 μC/cm 2 , and Ec = 11.5 kV/cm.