针对堆栈式六间隙串联气体开关，建立了6个放电间隙的光信号测量系统，实验获得了不同触发电压和气压时开关统计时延和形成时延的变化规律。统计时延占总时延约42%，形成时延占总时延约58%，触发电极相邻的两个间隙击穿时延占总时延约75%，是开关触发时延的主要组成部分。利用四分幅纳秒高速相机拍摄开关的放电通道图像，初步分析了放电通道的形成和变化过程，得到了不同实验条件下放电通道数量的变化规律。开关最底部间隙可以形成多通道放电，其他间隙以单通道为主。随着触发电压提高，触发间隙的放电通道数量明显增加，但是其他间隙变化不大。在放电过程中，没有观察到放电通道合并或熄灭的现象，间隙击穿后仍然有可能形成新的放电通道。

A suit of optical diagnostics, including a fiber array detector, a solar-blinded fiber detector and a framing camera, was used to investigate the discharging process on multi-gap gas switch. Experiments were carried out to study the relationship between the delay time and various switch parameters. The ratio of the statistical delay to all delay time was 42% while the formative delay was 58%, and the delay time of third gap and fourth gap were principal part of trigger delay. The evolution of channel arcs were acquired with a framing camera. The characteristic of discharge channel image and the change of discharge channel numbers with different trigger voltage and gas pressure were analyzed. The trigger voltage had a considerable influence on the channel numbers of trigger gap, while no obvious influence on other gaps. More channel numbers with higher trigger voltage were observed. There were not combination and extinguishment of channel arcs and new channel arcs might emerge.