Based on the transmission line code(TLCODE),a circuit model is developed here for analyses of main switches in the high pulsed-power facilities.With the structure of the ZR main switch as an example,a circuit model topology of the switch is proposed,and in particular,calculation methods of the dynamic inductance and resistance of the switching arc are described.Moreover,a set of closed equations used for calculations of various node voltages are theoretically derived and numerically discretized.Based on these discrete equations and the Matlab program,a simulation procedure is established for analyses of the ZR main switch.Voltages and currents at different key points are obtained,and comparisons are made with those of a PSpice L-C model.The comparison results show that these two models are perfectly in accord with each other with discrepancy less than 0.1%,which verifies the effectiveness of the TLCODE model to a certain extent. Based on the transmission line code (TLCODE), a circuit model is developed here for analyses of main switches in the high pulsed-power facilities. Since the structure of the ZR main switch as an example, a circuit model topology of the switch is proposed , and in particular, calculation methods of the dynamic inductance and resistance of the switching arc are described. Moreover, a set of closed equations used for calculations of various node voltages are theoretically derived and numerically discretized. Based on these discrete equations and the Matlab program , a simulation procedure is established for analyzes of the ZR main switch. Voltages and currents at different key points are obtained, and comparisons are made with those of PSpice LC model. The comparison results show that these two models are perfectly in accord with each other with discrepancy less than 0.1%, which verifies the effectiveness of the TLCODE model to a certain extent.