In this paper, an experimental setup was established to study the influence of potassium chloride (KCL) solution as the ground electrode on the nitrogen oxides (NOx) removal efficiency in non-thermal plasma (NTP) generated by dielectric barrier discharging (DBD) reactor. The experimental results show that the KCL solution as the ground electrode has better stability and higher discharge intensity and it is a promising approach to improve NOx removal efficiency. The specific NOx removal efficiency is related to the power frequency, the concentration and temperature of the KCL solution. As the power frequency increases, the NOx removal efficiency first increases and then decreases, and a maximum value is reached at the power frequency of 8 kHz. The NO removal effect is improved as the concentration of the KCL solution increases, especially when the concentration is lower than 0.1 mol/L. Under the same KCL solution concentration and input energy density, the NOx removal efficiency is increased with the solution temperature. In particular, when the power discharge frequency is 8 kHz, the KCL solution concentration is 0.1 mol/L and the solution temperature is 60 °C, the NOx and NO removal efficiency reach 85.82% and 100%, respectively.