In order to measure the arc voltage-current（V-A） characteristic of vacuum switch

a set of installation for researching the vacuum switch arc is designed in this paper. First a demountable vacuum chamber of short-gap and a trigging circuit based on cathode are built. The arcing trigging test is carried out for short gap in vacuum and the acquisition of the voltage and current of the arcing in vacuum is made in order to verify the V-A characteristic of arcing in vacuum. The results show that the designed system can trig the vacuum gap very well and can measure the V-A characteristic of arcing in vacuum switch precisely. It presents a good base for researching on the vacuum phase-controlled switch.