Because of high working pressure and uniform discharge, atmospheric dielectric barrier discharge (DBD) has become the main technology of non-equilibrium plasma discharge in recent years. Electrode structure isthe key factor in the ionization characteristics. Therefore, optimizing the electrode structure to improve ionization characteristics is very important for the development of plasma discharge equipment and the optimization of its performance. In order to enhance the ionization characteristics of dielectric barrier discharge at atmospheric pressure, high activity, low temperature plasma uniformity, coaxial dielectric barrier discharge device has been designed based on the ionization characteristics test and parameter diagnosis. Experimental researches on the effect of electrode structure of three grounding electrode on the spectral parameters were carried out by using photoelectric technology, and argon ionization tests were carried out under the conditions of a standard atmospheric pressure, discharge frequency 11.4 kHz and varied discharge peak voltage increasing from 5.4 to 13.4 kV (with 1.0 kV interval). Atomic emission spectroscopy (AES) was used to detect and analyze the excitation and splitting spectra of argon plasma, and the influence law and effect of electrode shape and applied voltage on the characteristic parameters of dielectric barrier discharge were obtained. The influence ofthe spectral parameters of threaded electrode, toothed electrode and cylindrical electrode, as well as the applied voltage on the characteristic parameters of DBD were studied. The results showed that the discharge intensity of the plasma of tooth shaped electrode is greater and the discharge effect is significant. The average energy utilization ratio of the electron is low, and the electron excitation temperature is weaker than that of cylindrical electrode. Under testing voltage conditions, the electron excitation temperature does not increase with the increase of applied voltage. It indicates that the main features of the micro discharge channel do not depend on the applied voltage supply, but depends on the electrode structure, gas composition and gas pressure. The increase in applied voltage only increases the number of micro discharge in unit time. The integration of electronic excitation temperature can reach up to 3 500 K, which accords with the typical characteristics of low temperature plasma.