Abstract: This article presents experimental results of the trigger characteristics of fast-pulse-triggered polymer-foil switch. The results show that the ratio of working voltage to self-greakdown voltage, the trigger voltage, the polarity and the distances between electrodes influence the switch’s performance significantly. The risetime of output pulse is smaller than 2ns that includes the risetime of measure system, the delay is 1~2ns and the jitter is sub-nanosecond. The delay and jitter decrease with raising the trigger voltage and the ratio of working voltage to self-breakdown voltage, and increase with enlarging the distances between main electrodes and trigger electrode. Among the four polarity combinations, the delay and the jitter are minimum for ‘p-n’, follow in sequence for ‘n-p’ an