Abstract: The synchronizer trigger system of Flash Ⅱ accelerator gas switch is designed and debugged. The system is composed of a synchro-control and a high voltage pulse generator, and the process includes the selection of synchronizer signal, filter, fast comparator, forestage trigger pulse formation, and the high voltage trigger pulse output. By filter circuit, the high frequent noise signal of Marx current is removed. By the fast comparator and the forestage trigger pulse circuit, the working point is accessed and a trigger signal is generated. The operating mode of the high voltage pulse generator switch is field distortion and preioniaztion, and its time response is 50 ns, jitter less than 5 ns. The experimental results indicate that the synchronizer system can generate a 100 kV pulse with ri