In this paper

the differences of the SPD TOV test methods between GB 18802.1-2002（identical to IEC 61643-1∶1998）and IEC 61643-1∶2005-03（2nd edition）were analyzed.The operating principle of the TOV test method in the new IEC standard was illustrated in detail while introducing the development of the TOV test equipment.Some SPD tests were carried out with the developed new TOV testing equipment.The testing results were discussed.The test method’s influence on the SPD performance and test results were shown.