It is important to reduce the jitter of gas switch under nanosecond pulse voltage for the output stability of electromagnetic pulse simulator. Especially under the condition that external triggering is inconvenient, the reduction of the jitter of self-triggered switch is worth paying attention to. In this paper, two types of self-triggered switches are designed, including the cathode grooved switch and the preionization switch. A nanosecond pulse experimental platform was built and the breakdown voltage, time delay and other parameters of the two types of switches are measured at three different pulse rise time of 40 ns, 70 ns and 120 ns respectively. With the use of data statistics and processing, the breakdown voltage and time jitter of the two switches are obtained. The experimental results show that the breakdown jitter of the switch can be effectively reduced by cathode grooved control emission or cathode preionization injection; The jitters of the two switches are between 1～1.8 ns under three rise time pulse voltages; Under the rise time of 40 ns and 70 ns pulses, the jitter of cathode grooved switch is shorter, which can be less than 1.2 ns, and the breakdown voltage dispersion is less than 1.29%; Under rise time of 120 ns pulse, the jitter of preionization switch is shorter than 1.6 ns.