Abstract: A numerical model of laser triggered SF6-N2 mixture switch is established on gas discharge physics. The photoionizations of SF6 and N2 are described by the double photon ionization model. The photoionization of hydrocarbon can be modeled as a three energy level system simplified from the model of Bischel W K. The mixture is heated by eletric field, and the heating ionizations of mixtures are considered.The calculated switch time delay is compared with that of experiment in the paper. The calculated values of laser triggered delay are in agreement with the experimental results. The delay of laser triggered SF6-N2 mixture switch increases as the percentage of SF6 in the mixture increases, and decreases as the energy of laser pulse, or the pressure increases.