The invention relates to the technical field of destructive tests for materials, in particular to a withstand voltage testing device for a rupture disk. The withstand voltage testing device comprises a fixed support, a fixed cover plate and a pressing mechanism, wherein a first through hole is formed in the fixed support and communicates with an external pressure source; a second through hole is formed in the fixed cover plate and communicates with the external pressure source; a to-be-tested rupture disk is located between the fixed cover plate and the fixed support and covers the first through hole and the second through hole; the pressing mechanism is used for pushing the fixed cover plate towards the fixed support so as to tightly press the to-be-tested rupture disk. According to the withstand voltage testing device for the rupture disk, the bursting pressure of the rupture disk can be tested rapidly and safely, the safety of a lithium ion battery adopting the rupture disk is guaranteed, and the lithium ion batteries in mass production coincide with design; a test mode of the device is more flexible, and the operation is simpler and more convenient.