Abstract: In the practical application of atmospheric pressure dielectric barrier discharge, air dielectric barrier discharge has an extensive industrial application prospect. At present, it is still difficult to obtain the uniform discharge of air, and there is still no uniform basis for the diagnosis of uniformity. In this paper, particle in cell (PIC) and Monte Carlo collision (MCC) methods are used to simulate the motion of particles in the discharge process, and the development process of air dielectric barrier discharge under atmospheric pressure is studied. Then, the influence of dielectric thickness and power supply frequency on uniform discharge is discussed, and the influence of these two factors on the generated plasma density is studied. The simulation results show that the current waveform without discharge filaments can be obtained when the thickness of the medium is d≥1.5 mm. When the power supply frequency is higher than 2.5 kHz, discharge filaments are difficult to avoid. Under the condition that uniform discharge can be formed, the medium thickness is appropriately adjusted around 1.5 mm, and the power supply frequency is increased, which will produce higher plasma density.