(NaxKy) (Nb0.885Sb0.08)–0.035LiTaO3 lead-free piezoelectric ceramics (NxKyNS–LT) with an excessive amount of Na or K were synthesized by conventional solid-state processes. Effects of Na/K ratio on structure and electrical properties of NxKyNS–LT ceramics were investigated. Excessive Na or K did not change the major crystal structure and barely influenced the sintering temperature, but excessive Na or K exhibited effects on grain size. Better piezoelectric properties of the ceramics were achieved when a certain amount of excessive K was added (the Na/K ratio before calcining was adjusted to 0.520:0.450). X-Ray fluorescence was used to examine the cause, and the enhanced properties are attributed to the formation of an MPB-like composition when the Na/K was changed. Specimens with properties of d33=183 pC/N, kp=0.33, Qm=103 were obtained in this work.