The utility model relates to a benzvalene form insulator seal pressure nondestructive test device, greatest stress that the settlement position of the same model through acquireing same electric pressure or the benzvalene form insulator of different models can bear, carry out air pressure test to the benzvalene form insulator that awaits measuring, at the atmospheric pressure within range set for apply pressure progressively, at this in -process synchronous record atmospheric pressure value and the stress at the settlement position of benzvalene form insulator of awaiting measuring, linear match is carried out to the stress, the atmospheric pressure data that obtain, obtains the relation that stress changes along with atmospheric pressure, combines greatest stress finds the solution the biggest bearing pressure of the benzvalene form insulator that awaits measuring. The utility model discloses outstanding completion the utility model purpose, can not damage the benzvalene form insulator, the equipment that adopts moreover can be obtained by current air -tight test apparatus improved, the cost is lower.