Abstarct: Abstract The aim of this research is to evaluate the removal percentage of Rhodamine-B dye from aqueous solution by atmospheric pressure plasma cooling technology. In this research, we designed two reactor models for the production of spark plasma and the effect of the main parameters of the color removal process, including color concentration (50-200 mg/liter), purification time (5-40 minutes), power supply voltage (6-10 kV), the pH of the solution (2.9-2.9), the type of electrodes (copper, aluminum, brass) and their distance from each other were investigated and the power of the device was also calculated. Experiments were performed in a volume of 50 ml using an alternating current (AC) electric power source to produce cold plasma. Examining the results of Rhodamine-B dye degradation showed that in the optimal condition of the experiments, the initial concentration was 150 mg/liter, pH = 4.2, the peak-to-peak voltage was 6 kV, the irradiation time was 40 minutes, and the distance between the anode and cathode electrodes was 2 cm with a decolorization percentage of 97.56. The obtained results indicate the direct effect of the initial voltage and retention time and the inverse effect of the initial dye concentration and pH on the removal efficiency. The results show that atmospheric pressure cold plasma can be well used for the treatment of coloured waste due to the absence of secondary pollution in the environment, no need for a vacuum system, low cost and high removal efficiency.