Abstract: The gas gap switch (GGS) has obvious advantages in the rapid control switch of a controllable arrester. However, the plasma jet in the high-pressure environment medium is severely restricted and can quickly induce a trigger failure. Therefore, it is necessary to study the characteristics of the plasma jet process to achieve a high-performance triggering and to conduct in high-pressure gas gap switches. Here, we established an experiment platform for researching the two-stage surface-triggered discharge performance induced by a gas gap switch jet plasma. The results show that we can divide the evolution of the gas gap switch jet plasma into three stages: high-pressure and high-speed jet, saturation and stabilization, and dissipation. The variations in the characteristic parameters of the jet plasma (jet area, jet height, and jet velocity) are different, and the jet plasma profile proliferates as a truncated cone. With the increase in the energy storage capacitance and the charging voltage, all the characteristic parameters of the jet plasma increase. However, the conduction time delay gradually decreases; the jet height during the induced breakdown also decreases significantly. The reduction in the duty factor inhibits the ability to form plasma. The evolutions of the compressed air and the SF₆ gap switch jet plasma are different. In addition, the SF₆ has a significant inhibitory effect on the development of jet plasma These results can guide researchers in improving the performance of high-pressure and large-capacity gas gap switches.