针对真空条件下干式脉冲电容器在额定工作电压以下较易发生闪络故障的情况,提出了一种新型真空脉冲电容的绝缘结构。分析了真空条件下大容量脉冲电容器的失效机制和解决方案；研究了3种不同绝缘材料沿面闪络电压，并进行相关理论分析；提出一种电容器整机灌封结构，该结构采用固体绝缘方式,避免了真空下的电容器低气压放电。通过对研制的真空脉冲电容器的测试表明，该脉冲电容器可以在10-2Pa及其以下气压的真空条件下可靠工作。

When dry-type pulsed capacitors of large capacitance are used in vacuum, flashover in low pressure area is inevitable. This paper analyzes the mechanism and solution for the flashover of the capacitors in vacuum. The surface flashover voltage of three different insulating materials is theoretically and experimentally studied. Finally, an overall-encapsulated capacitor is put forward, which uses solid insulation to prevent discharge in low pressure area in vacuum. Experimental tests show that this type of capacitor has strong mechanical strength and excellent electrical performance, and thus can work reliably in vacuum (lower than 10-2 Pa).