针对一种用于快前沿直线脉冲变压器(FLTD)的堆栈式多间隙气体开关，研究了电极表面粗糙度、电场不均匀系数、放电电流、气体压强等因素对开关自击穿电压分散性的影响。电极表面粗糙度0.1~0.8 μm时，击穿电压平均值没有明显变化，击穿电压分散性小于1.5%；电场不均匀系数为1.20和1.30时，电极烧蚀均匀，开关自击穿电压分散性小于2.0%；放电电流由1.1 kA增加到30.0 kA时，击穿电压的分散性增加了约2倍，电极烧蚀的作用明显增强；工作气压由0.04 MPa增加到0.30 MPa，击穿电压的分散性由1.5%增加到36%。初步分析了降低开关自击穿电压分散性的途径和方法。

The effects of surface roughness, field enhancement factor, current and gas pressure on self-breakdown voltage of a stackable multi-gap switch used for fast linear transformer driver are investigated. The mean self-breakdown voltage has no remarkable change and the dispersancy of self-breakdown voltage is under 1.5% when the surface roughness is 0.4 μm to 0.8 μm. The electrode erosion is symmetrical and the dispersancy of self-breakdown voltage is under 2.0% when the field enhancement factor is 1.20 and 1.30. The dispersancy of self-breakdown voltage increase almost two times as the current is changed from 1.1 kA to 30.0 kA. The dispersancy of self-breakdown voltage increases from 1.5% to 3.6% when the gas pressure is changed from 004 MPa to 0.30 MPa. Some methods of reducing the dispersancy of self-breakdown voltage are proposed．