Abstract: Plasma activated liquid (PAL) produced by atmospheric pressure gas-liquid discharge is a solution containing a variety of reactive oxygen and nitrogen species (RONS). Here, vertical falling water is used as the ground electrode to replace the inner center electrode in a conventional wire barrel discharge device. The effects of different applied voltage and initial solution conductivity on the physicochemical properties, inactivation efficacy and energy efficiency of PAL are investigated. The results show that the pH value of PAL decreases and the conductivity of PAL increases with the increase of applied voltage and initial solution conductivity. When the initial solution conductivity is 0.05~200 mS/cm, the concentrations of NO₃⁻, H₂O₂ and O₃ in the PAL increase with increasing the applied voltage and the initial solution conductivity. The NO₂⁻ concentration first increases and then decreases with increasing the applied voltage when the initial solution conductivity is 2.0~200 mS/cm. The NO₂⁻ concentration increases with the increase of applied voltage at the initial solution conductivity of lower than 2 mS/cm. PAL shows inactivation efficacy on bacteria with the increase of activation time. This study provides a new idea for selecting suitable electrodes for different environmental applications of gas-liquid discharge technology.