To avoid the overhead transmission lines suffering from the harm of lighting, a new type of Jet Stream Interrupter Gap Lightning Protection Device (JSGLPD) has been developed and applied, which is applied on 10Kv and 35Kv transmission lines. Improved mayr arc model is formulated to simulate the arc extinguishing capacity of by JSGLPD, when the arc is produced by Grounding short-circuit current. The velocity and working scope of jet stream is calculated with Two-dimensional N-S equation and k-ε turbulence model to get the losing coefficient of arc model, and the time coefficient is obtained though arc extinguishing experiment. Compared the simulation with waveform from oscillograph and the picture from high-speed camera in the low current arc extinguishing experiment, good agreement is found. So both the simulation and the experiment show the arc can be strongly and rapidly extinguished by JSGLPD.