The invention discloses an insulating bar voltage induction auto-disconnection device. Safety problems, for example, a common insulating bar can be easily used beyond a voltage class, and the distance between the top end of the bar and a live wire is smaller than the safety distance due to maloperation, are solved. The device comprises a device A (10) and a device B (11). An electromagnetic main switch (1) is used for controlling energization of an electromagnetic coil b (5) of the device B and an electromagnetic coil a (7), wherein the electromagnetic coil a (7) in the upper part is powered by a power supply connector (6) between the device A and the device B. The electromagnetic coil b (5) and the electromagnetic coil a (7) are mutually attracted and connected due to opposite polarities, and the electromagnetic coil b (5) and the electromagnetic coil a (7) are firmly connected through buckling devices (3) and (4). The upper and lower parts of the device are fixed at the ends of the bar respectively. When a voltage inductor (12) senses a dangerous voltage, a current reversing switch (2) is automatically switched in order to reverse the polarity of the electromagnetic coil b (5) of the device B (11), so that the function of automatically separating the device B (11) from the buckling device (3) and the device A (10) through repulsion of magnetic poles is achieved.