K0.5Na0.5NbO3 ceramics are considered as a potential candidate for PZT due to its excellent electrical properties and high Curie temperature. In this work, Cold sintering process (CSP) has been used in preparing the K0.5Na0.5NbO3-NaCl ceramics. Based on the experimental characterization, utilizing NaCl aqueous solutions as a transient solvent can change the grain microstructure of KNN ceramics, inhibit the volatilization of alkali metal elements, and lower the sintering temperature. As sintering at 900 °C, the electrical properties of the ceramic were Tc= 448 °C, d33= 115 pC/N, kp= 32%, and the obtained sample had an average grain size of 0.5 μm. The results indicate that CSP with NaCl aqueous solutions is an efficient method for low-temperature sintering of KNN ceramics with uniform grain size as well as good performance in electrical properties.