Abstract: The switching process of thyristor has been analyzed from the aspects of transmission carrier and carrier density. The effect of high current triggering on switching characteristics of triggered thyristor is investigated. Based on fast switching characteristics and flow capacity, high current trigger circuit has been designed. The relationship of switching characteristics with different triggering current and operation voltages has been studied. The experiment results indicate that the switching time of thyristor is determined by triggering mode and operation voltage. The delay time and breakdown time can be shortened by high current mode and high operation voltage, respectively, which can improve the switching characteristics efficiently.