Single-phase arcing ground fault is the main fault for the distribution work system, which brings great threat to power system. For this reason, this paper conducts a study on arc fault and focus on arc modeling and its effect on fault characteristics. Cassie-Mayr arc model is selected to describe grounding arcing characteristics. The ground model is set up and the typical voltage-ampere characteristic curve is obtained. Furthermore, the simulation results show that the V-I is influenced by the arc model and arc parameters. The parameters of the arc modeling are determined according to the structure features of the distribution network. Compared with individual Cassie arc model, Mayr model and constant resistance model, the simulation results using by Cassie-Mayr arc model are closer to practice, which demonstrates the validity and correctness of the model