利用二极管输出电压约1 MV、脉宽约40 ns的重复频率Tesla型脉冲功率驱动源，对大间隙、高气压的重复频率氮气火花开关进行了实验研究。通过将开关等效为RLC电路，利用测量得到的形成线电压与锥形段电压来计算氮气火花开关电阻。电阻的变化情况是放电开始时刻比较大，随着放电通道的形成，电阻迅速变小，最终达到Ω级的阻值。通过计算值与理论公式推算值比较，检验Barannik，Rompe-Weizel，Demenik，Toeple，Vlastos公式适用性，并尝试对Rompe-Weizel公式常数项进行了修正。

A repetitive Tesla pulsed power generator with 1 MV, 40 ns output was used to study the resistances of gas spark switch in nitrogen under high gas pressures and large gap. With the switch regarded as a RLC circuit, the resistances were computed under different gas pressures, by using the measured voltages of the pulse forming line and conical transmission line. The results show that the resistances reduce quickly during the formation of discharging channels, and eventually reach ohm level. Experimental and theoretical results are compared to check if Barannik, Rompe-Weizel, Demenik, Toeple, and Vlastos formulas are applicable. The Rompe-Weizel formula is modified by changing a different constant.