Abstract: Since the homogeneous discharge mode in dielectric barrier discharge has wide application potentials in various fields, the evaluation of dielectric barrier discharge uniformity has become the focus of research. The existing dielectric barrier discharge uniformity evaluation methods are mainly used to distinguish filamentous and uniform discharge modes, and it is difficult to qualitatively evaluate the dielectric barrier discharge uniformity. In this paper, a new method for evaluating the uniformity of dielectric barrier discharge in Ar using the dispersion normalization method and the regional temperature difference method is proposed, and the validity and versatility of the method are verified by parameters such as voltage, frequency, air gap spacing and carrier gas flow rate. The results show that the dispersion normalization method has universality and good stability. Through the chromaticity information of the discharge image space, the uniformity of the dielectric barrier discharge can be judged under different conditions. The temperature difference in the discharge area is calculated to realize the uniformity evaluation of the dielectric barrier discharge, and the high applicability of the regional temperature difference method is verified. The dispersion coefficient and regional temperature difference obtained by the dispersion normalization method and regional temperature difference method are inversely proportional to the discharge uniformity, thus quantitative analysis of discharge uniformity can be achieved. The method proposed in this paper can effectively judge the variation of discharge uniformity in Ar under different conditions, and provide a method basis for the characterization of dielectric barrier discharge uniformity.