In order to investigate the mechanism of dielectric barrier atmospheric pressure glow discharge(APGD) in Ar, an one-dimensional multiple particle self-consistent coupled fluid model is proposed. And the finite-element method (FEM) is used in the numerical calculation model, so the periodic evolvement waveforms of gas voltage, barrier surface charge density and discharge current density are investigated. The spatio temporal distributions of electrons, ions, metastable particles density and space electrical field are also obtained. The simulation results show that the charges accumulated on the barrier dielectric surface play an important role in ignition and extinguishment of the discharge. With the increase of applied voltage amplitude, the DBD breakdown occurs ahead of time, and discharge current density and the surface charge density increase gradually, which indicate that the discharge process becomes fierce. Furthermore, with the increase of relative permittivity of dielectric material, the discharge current density also gradually increases. The spatio temporal distributions of the particles density and the space electrical field show that the DBD breakdown occurs every half the AC period and the discharge under conditions considered in this model is a typical atmospheric pressure glow discharge(APGD), having an obvious cathode fall region, a negative glow region, and a positive column region.