Since the electromagnetic environment is getting more complex, the research of igniter electromagnetic protection receives extensive attention. In order to study the electro-explosive performances variations, the variation of the firing time and the firing-required energy were measeured under the condition that the SCB igniters were in parallel with varistors, and capacitor discharge and constant current experiments were adopted when the capacitance (47 μF) was charged to 22 V. Results show that there is no significant difference in the above parameters after the typical SCB igniter in parallel with varistor. But the low-energy SCB igniters are affected by varistor with lower breakdown voltage in the firing-required energy. The firing-required energy increase by 14%, while the firing time does not change. On the contrary, in the constant current duration of 100 ms experiment, varistor has no significant influences on SCB firing time and firing-required energy, indicating that varistor does not affect the SCB igniters′ electro-explosive performances dramatically when employed for the electromagnetic protection of the SCB igniters.